London-based millionairess Epifania (Sophia Loren) is attracted to Dr. Kabir (MD from Delhi and PhD from Calcutta), who is more intent on treating patients. When she persists, he confides in her that he had made a commitment to his late widowed seamstress mother that he will wed any woman who will manage to survive on just Rs.500/-, for 90 days. She finds out that this sum is equivalent to just 35 shillings but readily accepts this challenge. She also informs him that her late father had also imposed a condition that she must wed a male who will turn £500 into £15000 within the same period. Epifania then finds employment with an Italian firm, ends up re-organizing, and turning up the firm's profits. At the end of 90 days, she goes to meet Kabir and discovers that he has not only given all the money away but also has no interest whatsoever in marrying her.