It's 1977 and having survived a train accident several years earlier, Ashoke Ganguli (IRFAN KHAN) agrees to wed Ashima (TABU) in an arranged marriage that transplants her from Calcutta to New York City, a world completely foreign to her. It's not long before they have kids, the first being given the temporary birth name of Gogol after Ashoke's favorite writer.
Years later, Gogol (KAL PENN) is a teen who gets grief from others about his name, unlike his younger sister, Sonia (SAHIRA NAIR). Even so, and due to being born in the states, both kids are far more comfortable with American culture than their parents.
Years later, Gogol's in college dating Maxine Ratcliff (JACINDA BARRETT), daughter of rich, socialite parents, exposure that seems to be removing him even further from his ancestral culture, at least in the eyes of his parents. When he eventually starts seeing Moushumi Mazumdar (ZULEIKHA ROBINSON), that goes over a bit better, due to the fact that she's also Indian.
From their arrival in America through the birth and raising of their kids, the Gangulis try to stay together as a family through various trials and tribulations that come their way during the intervening decades.