The movie was loosely adapted by Charles Lederer (with uncredited rewrites from Howard Hawks and Ben Hecht) from the 1938 novella "Who Goes There?" by John W. Campbell, Jr. (originally published under the pseudonym Don A. Stuart). It was directed by Hawks (uncredited) and Christian Nyby for Hawks' Winchester Pictures, which released it through RKO Radio Pictures Inc.
The film took advantage of the national feelings of the time to help enhance the horror elements of the story. The film's release in 1951 coincided with the Korean War and the upswing in anti-communist feelings brought on by McCarthyism and by the territorial ambitions of Stalinist Russia. The idea of Americans being stalked by a force which was single-minded and "devoid of morality" fit in well with the parallel feelings of the day on communism. Equally the film reflected a post-Hiroshima scepticism about science and negative views of scientists who meddle with things better left alone. In the end, it is American servicemen and sensible scientists who win the day over the monster.
After being briefed by Dr Carrington, Hendry's crew & the scientists land at the crash site. They are shocked to discover that the shape of the craft is round - a flying saucer - with an airfoil of somesort protruding from the surface. They all agree to free it from the ice with thermite heat explosives, but in doing so, accidentally destroy the craft. However, the crew chief (Dewey Martin) has a geiger counter & locates a body nearby frozen in the ice.
They excavate the tall body, preserving it in a large ice block and return to the research outpost as a major storm moves in, making communication with Anchorage very difficult. Some of the scientists want to thaw out the creature immediately, but Hendry orders everyone to wait until he receives orders from Air Force authorities. Feeling uneasy guarding the body, Cpl Barnes (William Self) covers the ice block with a blanket, not realizing it is an electric blanket, and the creature thaws out, revives and escapes to the outside cold.
The creature is attacked by sled dogs, and the scientists recover an arm, bitten off by the dogs. They examine the arm and as it warms and ingests the blood from one of the dogs, it begins to come back to life. They learn that, while appearing humanoid, the creature is in fact an advanced form of plant life. Dr. Carrington is convinced that the creature can be reasoned with, while the Air Force men are just as sure it cannot and may be dangerous. But Carrington soon realizes that the creature requires human blood to reproduce.
Carrington later discovers the hidden body of a sled dog, drained of blood in the greenhouse. He has volunteers from his own team, Dr Stern (Eduard Franz) & Dr Vorhees (Paul Frees) to stand guard overnight, waiting for the creatures return.
Later, Carrington secretly uses plasma from the infirmary to incubate and nourish seedlings he has taken from the arm, failing to advise his colleagues or Capt Hendry of what he has done, or of the now-dead bodies of Stern & Vorhees, drained of blood. Nikki reluctantly updates Hendry when he asks about missing plasma. Hendry confronts Carrington, but the creature returns & the USAF crew, after failing to affect it with firearms, trap it in the greenhouse. The scientists soon realize that the wounded creature will need more blood, and that it will not be confined for long.
Nikki notes that the temperature is fast dropping, & Hendry relates that it's probably due to a cut fuel line. The creature soon escapes and breaks back into the camp. But Captain Hendry and his men set it alight with kerosene (following a suggestion from Nikki about how to deal with vegetables - "boil them, fry them?") and it flees into the snowy night.
The cold forces the scientists and the airmen to make a final stand in the generator room. The crew chief suggests that electricity is hotter than flaming kerosene, and they immediately create a walkway trap for the creature using high voltage electricity on overhead leads as a weapon. As the creature advances on them, Carrington twice tries to stop the creature's demise; once by shutting off the power, and the second by running out onto the trap and trying to reason with the creature. He fails and the creature throws him aside.
The creature is electrocuted, shrinking to a husk as it is killed. Its seedlings are also destroyed. As the film closes, Hendry and Nikki are set to become engaged as Scotty files his "story of a lifetime" by radio, imploring his listeners to "Watch the skies!"
When American Movie Classics showed the movie in the 1990s, the introduction related a story about the creation of the creature's makeup. The makeup artist supposedly went through several revisions of the creature's face. He would test each one by putting the full makeup on Arness and taking him for a drive through Los Angeles. At one point, a woman in the next car screamed and fainted upon seeing the creature. The makeup artist "knew he had a winner" and used that face in the movie.
As is common in many of Howard Hawks' films, the dialogue is notable for its snappy, fast pace and overlapping style, with characters (major and supporting) often speaking over each others lines in a realistic way. And that Hawks likes to have a smart, capable woman as a character in his films.
One of the film's actors, William Self, later became President of 20th Century-Fox Television.
An 81-minute version of the film also exists. This shorter print, which deletes some sequences of character development, was prepared for a theatrical re-release and has also been shown on television.
Certain elements of Carpenter's film were heavily suggested (including the "burning letters" opening titles) by this film. Also during The Thing, the characters make reference to a 'Norwegian' team that used thermite charges to clear the ice around the UFO, this is a direct reference to the team in the original film.
Scotty: I'm not, therefore, going to stick my neck out and say that you're stuffed absolutely clean full of wild blueberry muffins, but I promise you my readers are going to think so.
Scotty: An intellectual carrot: the mind boggles!
Scotty: Watch the skies, everywhere! Keep looking. Keep watching the skies! (last line)