Tohfa in which is about Janaki (Jayaprada) and Lalita (Sridevi) are sisters, who love each other dearly. Lalita and Ram (Jeetendra) fall passionately in love with each other. Unknown to them, Janaki is also in love with Ram. When Lalita finds out, she decides to sacrifice her relationship with Ram. In haste, she marries a good-for-nothing man (Shakti Kapoor), who is arrested by the police immediately afterwards. Unaware of Lalita's true motive, Ram and Janaki are furious with her. Lalita moves away and is not seen for several years. Ram and Janaki get married and live happily; their only sorrow is their inability to have children. Many years later, Ram meets Lalita again. She is working in an office and singlehandedly bringing up her son. To his shock, Ram realises that he is the father of Lalita's son. The child had been conceived in a moment of passion between Ram and Lalita before they had separated. Ram is torn between his loyalty to his wife Janaki and the pull of affection towards his son. Janaki, now expecting a child, finds out about her sister's reappearance but misunderstands the whole situation. She begins to suspect Ram and Lalita of cheating on her. However, at last, all the misunderstandings are cleared up. The true extent of Lalita's sacrifice becomes known to Janaki, who feel very guilty. Janaki gives birth to a daughter and passes away, leaving the baby and Ram in Lalita's care.