Set against the backdrop of World War II on a tropical island, a U.S. Navy nurse named Nellie Forbush falls in love with a French expatriate, Emile de Becque. As Nellie grapples with her feelings for Emile, she is confronted with her own ingrained prejudices, particularly when she learns about Emile's mixed-race children from his late Polynesian wife. While their romance unfolds, the military seeks Emile's assistance for a crucial reconnaissance mission behind enemy lines.

Meanwhile, a secondary romance blossoms between Lieutenant Cable, another American officer, and Liat, a young Tonkinese woman. This relationship is also strained by issues of race and cultural differences. As the war intensifies, the characters are forced to confront their feelings, prejudices, and the harsh realities surrounding them. The story explores themes of love, race, and the impact of war, ultimately leading to pivotal decisions that shape the futures of both couples and the military endeavors they are a part of.