The film, presumably set in a small town on the New Jersey Shore in the 1950s, tells the story of two immigrant brothers from Italy who own and operate a restaurant called "Paradise." One brother, Primo (Tony Shalhoub), is a brilliant, perfectionist chef who chafes under their few customers' expectations of "Americanized" Italian food. Their uncle's offer to return to Rome to help with his restaurant is becoming more and more appealing to Primo. The other brother, Secondo (Tucci), is the restaurant's manager, who is enamored with the possibilities presented by their new endeavor and life in America. Despite Secondo's efforts and Primo's magnificent food, their restaurant is failing.

Secondo's elusive success as a businessman makes him unable to commit to his girlfriend Phyllis (Minnie Driver), and he has recently been sleeping with Gabriella (Isabella Rossellini), the wife of a competitor. Her husband's self-named restaurant, Pascal's (Ian Holm), has enjoyed great success despite (or perhaps due to) the mediocre, uninspired food served there. Desperate to keep Paradise afloat, Secondo asks Pascal for a loan. Pascal demurs, repeating a past offer to have the brothers come work for him. This Secondo in turn refuses; he and his brother want their own restaurant. In an apparent display of generosity, Pascal instead insists that he will persuade Louis Prima to dine at Paradise when he comes to town; the celebrity's patronage should revitalize the brothers' business. Primo and Secondo plunge themselves into preparations for this "big night", inviting dozens of people to dine for free and spending what little they still have on planning a magnificent, extraordinary feast. Primo pours his heart into each dish, lavishing care and attention on the cooking.

As they wait for Prima and his entourage to arrive, the crowd indulges in the exquisite food and partakes in a fabulous celebration. Hours pass, however, and it becomes apparent that the famous trumpeter is not coming. As the attendees begin to file homeward, and at Gabriella's insistence, Pascal admits that he never called Louis Prima, the singer is not coming.

Phyllis catches Secondo and Gabriella kissing and runs away to the beach where she has a final quarrel with Secondo. Primo and Secondo have a fiery, heartbroken argument, chafing at their mutual differences. In the wee hours of the morning, Pascal admits to Secondo that he set the brothers up for failure; not as revenge for Secondo's affair with Gabriella but because then the brothers would have no choice but to either return to Italy or work for Pascal. Secondo denies him, saying they will never work for him. The film closes with an uninterrupted, nearly wordless long take: as dawn breaks, Secondo silently cooks an omelette. When it is done, he divides it among three plates, giving one to Cristiano (Marc Anthony), their waiter, and eating one himself. Primo hesitantly enters: Secondo hands him the last plate. They eat without speaking, but lay their arms across each others' shoulders as they do so.