Nirmala Gupta (Dina Pathak), wife of Dwarka Prasad Gupta (Ashok Kumar), runs her household very strictly. While most of her family resent this, they obey her instructions to be on her good side.
Things start to change after her second son gets married to Anju. Manju (Rekha), Anju's sister, comes over to stay for a few days with the Gupta family. Manju resents the way Nirmala treats people and feels some permanent changes are needed in the household. She begins to stir up trouble as she slowly convinces the others that it's OK to speak one's heart and break the rules sometimes. Everyone in the household is enamored by Manju's vivaciousness and fun-loving spirit, except Nirmala who considers her antics childish and irresponsible.
One day while all other members of the family except Nirmala are away from the house for three or four days, leaving Manju in the house, Dwarka Prasad suffers a heart attack when he verbally attacks his wife for being unfriendly and harsh towards Manju. Nirmala then realizes Manju's responsible and caring attitude as she helps Dwarka Prasad receive medical treatment and takes care of him.
The movie ends with Manju marrying Nirmala's third son Inder (Rakesh Roshan) as she is accepted by Nirmala.