Mukhya Mantri is the story of a poor school teacher Bimal Choudhury who is forced by his family members to contest state legislative elections against the corrupt MLA Bibhash Choudhury. The Chief Minister announces that hell make Bimal the CM if he wins the election as he was sure he won't win the election. But the well-wisher of people who helps people in need is a popular figure in the village. Gradually Bibhash and the CM realize it'll be difficult to defeat him. They try to harm him, his family and supporters. A widow loses her life for him. Bibhash and his son are arrested by the police. Bimal finally decides to withdraw from the election as he doesn't think he is fit to make false promises like politicians.