Waqt is the story of a father and a son between whom there is a special bond. Unlike many other father son relationships, these two are more like friends; the father being Ishwar Sharawat (Amitabh Bachchan) and his son Aditya (Akshay Kumar). Ishwar is the owner of a toy manufacturing company and is extremely generous and big hearted making sure to spread as much as joy to kids as he can, and that is why he makes sure that during the festive season of Diwali he distributes toys to the orphans. On the surface Ishwar's life seems like something every man would crave for; a great and profitable business, a loving son and a caring and dutiful wife Sumitra (Shefali Shah) or so it seems.

Aditya is in love with Mitali (Priyanka Chopra) and vice-versa who is the daughter of Nathu (Boman Irani). However after the initial problems that occur, the two of them finally end up getting married. Ishwar hopes that marriage will make Aditya a more responsible man but he is disappointed. His efforts to turn Aditya into a more responsible individual turn futile.

One thing leads to another and Ishwar doesn't have an option but to throw Aditya out of the house. Aditya is shocked that the same doting father is now behaving in this fashion towards him and his now pregnant wife. After the initial problems, Aditya takes it upon himself to take care of his wife and his unborn kid. Aditya starts working as freelance stuntman and at the same time prepares for a star search contest. Aditya starts turning into an independent man but the rift in the relationship between him and his father grows.

In the climax of the film Aditya has been chosen to participate in the finals of the star search contest and this is where all the reasons of the father's cruel behavior are exposed and this forms the end of the story when the father and son get back together.