Set during World War II, the film tells the story of a motley crew of American GIs who go AWOL in order to rob a French bank, located behind German lines, of its stored Nazi gold bars.

The film stars Clint Eastwood and Telly Savalas, and co-stars Don Rickles, Carroll O'Connor, and Donald Sutherland providing the comic absurdity, with secondary, comedic roles by Harry Dean Stanton, Gavin MacLeod, Karl-Otto Alberty, and Stuart Margolin.

In 1944 France, during World War II, United States Army Private Kelly—a former lieutenant scapegoated for a failed infantry assault—captures Colonel Dankhopf of Wehrmacht Intelligence.

Finally, Kelly broaches his plan to Big Joe's platoon who, disillusioned with the pointless battles, being bombed by their own side, and risking daily death for a low salary, eagerly join him.

To avoid drawing attention, Kelly's infantrymen travel separately from Oddball's unit, who fight their way through the German lines and destroy an enemy-held railway depot.

Meanwhile, their radio messages are intercepted by allied command and Major General Colt, who misinterprets them as efforts by an aggressive Army unit independently pushing through the previously unmoving battle lines.

Kelly's men infiltrate Clermont and, under the cover of the ringing church bells, eliminate the German infantry, while Oddball's unit tactically destroys two of the three superior enemy Tiger I tanks.

At Crapgame's suggestion, Kelly, Big Joe, and Oddball approach the Tiger to offer its commander a deal, surmising that he is, like them, a soldier following orders, unaware of the gold in the bank.

On 10 December the editor, Norris D. McWhirter, wrote back to Morgan, stating that he had very little information and that he essentially suspected that there had been a cover-up, which required that the story should be subject to a "restricted classification"[citation needed].

He closed by suggesting that until that security classification was changed, "due to death or eflux [sic] of time, "any film made will have to be an historical romance rather than history"[citation needed].

[7] The investigation finally led to two of the missing gold bars (valued in 2019 at over $1 million) being handed over by German officials to the U.S. government in a secret ceremony at Bonn on 27 September 1996.

[11] Location shooting was done in Yugoslavia, in the Istrian village of Vižinada, in the city of Novi Sad,[12] and the ruins of the Beočin palace (in present-day Croatia and Serbia respectively), and finally in London.

[20][21] Some of the deleted scenes were shown on promotional stills and described in interviews with cast and crew for Cinema Retro's special edition article about Kelly's Heroes:[22] The film score was composed, arranged, and conducted by Lalo Schifrin, while the soundtrack album was released by MGM Records in 1970.

The website's critical consensus reads: "Kelly's Heroes subverts its World War II setting with pointed satirical commentary on modern military efforts, offering an entertaining hybrid of heist caper and battlefield action".

[29] Roger Greenspun of The New York Times described the action scenes as "good clean scary fun," until it goes "terribly wrong" when many soldiers are killed and "the balance alters to the horrors of war.

[30] Arthur D. Murphy of Variety called the film "a very preposterous, very commercial World War II comedy meller, the type which combines roadshow production values and length with B-plot artistry".

Despite his artful efforts, his role as a long-haired hippie tank commander is so ludicrously out of time and place that it becomes hard to stomach in a film in which, elsewhere, two GIs trapped in a mine field are gunned down like cans on a stump.

[34] The Monthly Film Bulletin stated: "In terms of rip-roaring, bulldozing action, this attempt to cross The Dirty Dozen with Where Eagles Dare can be said to have achieved its object".

However, the review went on: "With all energy apparently expended on sustaining over two hours of consistently devastating explosions, pyrotechnics and demolition, little attention has been paid either to period detail (resulting in mini-skirted townswomen and the description of conditions in terms of 'hung-up' and 'freaked out') or to the script, which is jolly, vituperative, and little else".