Two marines, Top Sergeant Flagg and Sergeant Harry Quirt, are continually falling out over their women.  In Russia they meet a firebrand named Katinka, in Brooklyn a wise-cracking flapper from Coney Island, and in the tropics a Spanish siren named Elenita.

The two pals are separated when Flagg goes on a reconnaissance mission by plane, leaving Quirt, who has contracted fever, behind.  After a battle episode in which Flagg leads his troops to victory, he and Quirt, now fully recovered, argue about which of them is the father of Elenita's child.

That settled, the regiment (and Flagg and Quirt) prepare to return to the States.