Billy Wilder adapted the play by Donald Bevan and Edmund Trzcinski and directed this POW story that combines humor, a spy mystery, and escape.
In a German prisoner-of-war camp Manfredi (Michael Moore) and Johnson (Peter Baldwin) get ready to escape, and Sgt. J. J. Sefton (William Holden) asks if they calculated the risk. They crawl under the barracks and run to a wash room, where they go down into a tunnel. Sefton bets cigarettes they won’t get out of the forest. Manfredi and Johnson climb out of the hole and are killed by machine-gunners. The men hear the shots, and Sefton collects his winnings.
Sgt. Johann Schulz (Sig Ruman) wakes them up at 6 a.m. for roll call. They see two bodies on the ground covered. Col. von Scherbach (Otto Preminger) asks them not to ruin his perfect record; nobody has escaped from Stalag 17. He says they will lose their stove and fill in the tunnel. In the wash room Duke (Neville Brand) asks how they knew about the stove and the tunnel. They run to see the new Russian women. “Animal” (Robert Strauss) falls in the mud, and he and Harry Shapiro (Harvey Lembeck) miss the potato soup that gets used for washing socks. Sefton has a fried egg he bought with the cigarettes. After Marko (William Pierson) makes anouncements they are loaned a radio. They string a wire, and some play volley ball. They hide the radio before Schulz comes in. They joke with him, and Duke asks him who is tipping them off. After they go out, Schulz sees a light bulb used as a signal and finds a note in a chess piece.
Sefton runs a horse-racing game and takes bets. Cookie (Gil Stratton) starts the rats running. Animal loses and blames Harry. Animal kisses his picture of Betty Grable. Sefton sells them alcohol. Cookie sells time on a telescope looking at a delousing cabin for women. Sefton admits he bribes the guards to run his businesses. Animal and Harry paint a white line to get out the gate and visit the women in the delousing line. A guard stops them at the window, and they run back.
Marko brings in the mail, and Shapiro gets the most letters. Animal reads Joey’s letter to him. Harry’s letters are from the finance company wanting payments. Lt. James Dunbar (Don Taylor) arrives, and Sefton remembers Dunbar as rich. Dunbar warns Sefton not to insult him, and Sefton goes out. The men put on mustaches to look like Hitler and salute Schulz. He says they will get clean blankets, and he asks for the radio. He finds it in a bucket of water. Schulz sees the signal and sends them all out so he can exchange the chess piece.
Men suspect the missing Sefton traded the radio, and they find his trunk full of loot. Duke comes in and shows them Sefton outside the gate. Sefton returns to icy stares and says he had a good time. He sees his trunk open. Duke says Sefton is the stooly, but Sefton says it is someone else. Col. von Scherbach comes in and invites Lt. Dunbar to his quarters for having bombed an ammunition train. Bagradian (Jay Lawrence) who came in with Dunbar says they said nothing until they got into that barracks. Some men beat up Sefton.
Sefton offers Schulz cigarettes and asks who is the spy. Duke and others threaten Sefton again. The Geneva inspector comes in and asks for complaints, but having been threatened, no one says anything except about Dunbar being arrested.
Exhausted Dunbar tells Col. von Scherbach that he didn’t do it. He tells Dunbar he will be taken to Berlin by the SS for interrogation. The inspector comes in and asks about Lt. Dunbar. Von Scherbach says it was sabotage, and the inspector warns him about war crimes trials later.
Sefton lets Duke take his distillery to trade it for the phonograph. “Security” Price (Peter Graves) sees the signal and exchanges the chess piece. Sefton notices the light bulb and suspects it is the signal. Sgt. Hoffman (Richard Erdman) questions Bagradian, and he explains how their time bomb worked. Duke takes bottles from Sefton’s trunk for the Christmas party. Animal and Harry give Joey (Robinson Stone) a flute, and he plays it. A siren is heard, and Schulz makes them all get out. Price stays behind and talks to Schulz in German, showing him a flaming device. They leave, and Sefton has heard them.
During the party Sefton tells Cookie the Germans may have planted an agent in the barracks. Cookie asks who it is. Sefton wonders what can be done. Animal dances with Harry and sings, thinking he is dancing with Betty Grable. Harry wakes him up, and he cries. Hoffy and Marko tell people to drift out. Price offers to talk to Schulz. Sefton says they should watch out for him, and he persuades them to have Price stay inside with Sefton. Price tells Sefton he does not like him.
Outside they create a diversion as Dunbar is led to a car. A lame man places a smoke bomb by the car. The Germans make all the men show their dog-tags while searching for Dunbar, who is hiding in a water tank. In the barracks they draw one dog-tag to see who will try to get Dunbar out. Price volunteers, and the others agree. Sefton blocks the trap door and pulls out a knife for the stooly. Sefton says Hoffy told the stooly where Dunbar is. Sefton asks Price if he speaks German and says he is a Nazi. Sefton shows how he used a chess piece to pass notes and made the light a signal. Price tries to escape, and they grab him. Sefton offers to help Dunbar escape by using Price as a decoy. Hoffy and the others agree.
Sefton says goodbye and crawls under the barracks and goes to the water tank. Dunbar climbs out, and Sefton massages his cold legs. The men throw Price out the door, and he is shot. Sefton and Dunbar run to the barbed wire, and Sefton cuts it. They escape. Col. von Scherbach and Schulz see the man killed is Price. The men get back on their bunks and realize the two men escaped.
This black comedy uses irony and sarcasm to rise above the brutality of war imprisonment. The enterprising American is suspected of treachery because he is often making a profit off the others. Yet the loyalty of the Americans is affirmed, and the foolishness of the Germans is satirized.