Muskaan film starts off as a love story, gets into the groove of a love triangle. Dashing and debonair fashion designer Sameer Oberoi (Aftab Shivdasani) has everything going for him, a successful career; a secure future; a comfortable and wealthy lifestyle; a beautiful girl Shikha (Anjala Zaveri) who hopes to marry him, what more could anyone want?
But Sameer has an image of his dream-girl in his mind, and he hopes to find her soon. His search for her meets with obstacles of searching for a better model; a series of wrong telephonic connections, all connecting him to a young lady. His group decides to travel to another location, and the young "wrong number" lady, named Muskaan (Gracy Singh) also travels in the same bus, leading to some more misunderstandings.
Sameer takes a liking to Muskaan, and decides to appoint her as his new model, to which she agrees. Then their world is turned upside down when Jahnvi (Neha) a member of their group is brutally murdered, and the only clue the police have is that her killer's name begins with an "S", and Sameer becomes a prime suspect in her murder, and in the eyes of Inspector Vikram Rajput (Gulshan Grover), who is determined to get the killer at any cost.