I must be old!
I saw this movie at a drive-in theater with my parents when I was about 10 years old. It was better back then.

"I shall make the Earth my home, and I shall never leave it..."
Anyone who calls TEENAGERS FROM OUTER SPACE "one of the worst movies ever made" has their head on backwards; have they ever seen "Manos The Hands of Fate", or "Beast of Yucca Flats"? If not, watch those two, and get back to me if you still think this is one of "the worst"...
TEENAGERS is a strange film; a labor of love with flashes of real talent and ingenuity between the easy-laugh fodder of toy zap-guns and giant lobsters. Its earnest, heart-on-its-sleeve nature is what really makes it a target for today's jaded, cynical audiences.
The movies' ace, however, is Dawn Bender(aka Dawn Anderson) as "Betty"... is there any male viewer out there who doesn't have a thing for her? Her unusual beauty and oddly convincing performance(even when being threatened by lobster shadows or simulating romantic tension with an obviously gay David Love) reminds me of those spooky female sung 50s ballads like "A Thousand Stars" or "Angel Baby". It's really too bad she didn't go on to bigger and better things.
The MST3K crowd can goof on TEENAGERS... all they want, but there really is nothing else quite like it...and that's more than you can say for all the big-budget cookie cutter drivel that comes out of Hollywood today.

Those Crazy Kids
A group of aliens are scouting the universe in search of a planet where they can raise giant lobsters for their food supply. Unfortunately it's Earth they choose, but you do have to appreciate their taste in fine dining. One of the "Teenagers" called Derek(an alien name if I ever heard one) has a soft spot for inhabited planets and goes AWOL, leaving the other aliens to go back to their planet to pick up the load of giant lobsters(goes to show teenagers are rebellious regardless of where they're from). Derek befriends a hot chick named Betty and her grandfather and attempts to live a peaceful earth life. That's quickly shattered by one alien called Thor who stayed behind to find and capture Derek. Thor goes on a rampage trying to find Derek, killing everybody who gets in his way. The weapon of choice for these aliens is a nifty ray gun that lights up and reduces people to bones. Then it's a game of cat and mouse involving Thor, Derek, Betty, and of course Gramps. But wait, there's more! The original guinea pig lobster has now grown to monsterous size and is killing folks and making it's way towards the town. Derek is now caught in a pickle as he has to stop the monster and the forthcoming invasion, but now has feelings for Betty and is quite eager to learn the many wonderous delights of the human female. Will he succeed?
This is a better than average "bad" 50s sci-fi flick. It's got all the schlock fixins for the genre with a more interesting plot. Sure there isn't a single teenager in the film(they all look to be in their 20s), the bones of the victims look like the same skeleton from a school classroom simply laid out in various locations, and the giant lobster is a a shadowy image of a real lobster superimposed onto the film. But hey, these are the kind of things we love about these films, right? Horror fans will notice that most of the music on the soundtrack is the music that would be used throughout Night of the Living Dead years later, and it is hard to hear that music without thinking of that film. A fun little movie is you like this kinda stuff, and you damn well should if you're reading a review page of this movie.

Ludicrous, Horrendous, and Often Entertaining If You Go In For That Sort Of Thing
While most bad films are simply bad and that is all, now and then you encounter one SO bad that it becomes amusing. TEENAGERS FROM OUTER SPACE is all of that and then some, so ludicrously, incredibly bad that it more or less ended the careers of every one associated with it.

An all-male, teenage crew of aliens land on earth to see if they can grow their cattle, a creature they call "gargons," on it. When good-boy alien Derek (David Love) realizes the planet is inhabited, he takes off to warn the earthlings, with bad-boy alien Thor (Bryan Grant) in hot pursuit. Both meet a lot really bad actors, including Dawn Anderson and Harvey B. Dunn, and Thor reduces several of them to skeletons clearly borrowed from a high school science lab for cinematic purposes. In the mean time, the test-case gargon grows and grows to man-eating size, and we are startled to realize that it is actually a really big lobster--or, more accurately speaking, the really big shadow of a regular sized lobster used in the hope that viewers will be terrorized.

Ah, no, not really. There are lots of horrendous things going on here, and some of them may actually make you close your eyes, but if you do it will be more out of embarassment for the players than out of fear. Yes, it really is that bad, and it is dosed up with some truly uninspired Cold War allegory for good measure. The whole thing is impossibly dire, and you are in the right frame of mind it can actually be extremely entertaining in a sort of sado-maschochistic kinda way. Drug use would probably also help.

The film quality is very ify. The contrast is atrocious and the first few scenes are riddled with artifacts, and while both issues get a bit better as the movie progresses they are never really resolved. And let's be honest: this isn't a quality product, so it probably never looked all that great even in its first run. Recommended, but only if you have a taste for the worst of the worst in late 1950s B movies; all others will likely find it so cringe worthy that they can't get past the first few minutes.

GFT, Amazon Reviewers

low budget, poor acting, so bad it's good!
Actually, this movie is not as bad as I remembered it. But there are a lot of issues.
To start with,I guess you would have had to have lived through the fifties to understand the significance of the title. At that time, the word "teenager" was actually synonymous with "juvenile Delinquent" or the modern term "gangster". Normal people of that age were "youths", "young adults" or some other neutral term. "Teenagers" were hormone-driven bundles of rage and rebellion. To imagine such recklessly destructive persons equipped with alien weapons capable of mass destruction was to trigger every parents darkest nightmare.
The story line is pretty thoughtful. We have an alien civilization which is what might have happened if Hitler or Stalin had taken over the world. Children are raised in farms and never know their parents, except for those of high party members, who are not told until maturity.
The main food source for this civilisation is the gargon, a crustacean-like creature which eats anything or anyone that it can catch and being quite huge, it can catch just about anything.
In the opening a scout ship from this civilition lands near an American town. It is crewed by one adult and two teenaged helpers. Their mission is to place a specimen of gargon on Earth to see if it will prosper there. One of the teenagers detects signs of human life and argues against planting the voracious gargons here. He is apparently a member of an underground working against the oppressive government. The other teenager can best be described as a Hitler Youth with ambitions of becoming an SS thug. The good teen is threatened with arrest and runs away. The adult leader then reveals that he is really the son of the Party Leader and must be brought home safely. A small gargon is left in an abandoned mine and the vicious teen is left behind to hunt down and arrest the escapee. The next act of the movie sees the good teen becoming more and more fond of Earth's way of life, while the vicious teen hunts for him, leaving a trail of bodies reduced to skeletons by his ray gun. The vicious teen is eventually captured and his ray gun damaged.
Meanwhile, the gargon has grown huge and broken loose from the mine. It is now roaming the countryside, killing everything and everybody in sight. The good teen struggles to repair the ray gun and finally, using power from a high voltage line, uses it to destroy the gargon.
The scout ship returns bringing the Party Leader intent on recovering his son, and leading a fleet of ships carrying large packs of gargons to be released on Earth.
The good teen seizes control of the scout ship's radio and causes the whole fleet to crash on him, killing the evil teen, the Party Leader, all of the gargons, and himself. By his sacrifice, he saves the Earth and opens the way for revolution on his homeworld.
I think that the reason that this movie hangs on as a cult favorite is that it really is a good basic story. With a good script and and a more experienced director, as well as a good budget for special effects, this could have been a classic. the cast and crew did the best they could with the resources available to them, but those resources were limited and it shows in the finished product. The main complaint, as it is with so many of these low budget movies is wooden acting. A good script writer would have given them the language to express the concepts they were clearly trying to explore, and a good director would have guided them in better ways to perform the lines. Budget enters in too, since they clearly could not afford the film needed to repeat unsuccessful takes.
Bad marks for special effects. The ray gun is clearly a flashlight with a fancy pistol grip and a few useless decorations. But the worst effect is the gargon. It is clearly the shadow of a half dead lobster superimposed over the screen. In the hands of a good stop action animator it would have been a prize-winning effect, but that would have cost more than three times the whole budget for the movie. Such animation is expensive and time consuming.
we really should give good marks for costume. The Alien uniforms really look authentic down to the white footgear.
This movie was originally released on the same bill as "Gigantis, The Fire Monster", Which has recently been released in its original Japanese title as "Godzilla Raids Again". For an evening of fun watching, buy them together.
"Teenagers From Outer Space" is priced low enough to be worth the effort.