The Best Man is a romantic comedy film that revolves around a group of friends, one of which is getting married. Harper Stewart (Taye Diggs) lives in Chicago with his girlfriend, Robin (Sanaa Lathan). He has just finished writing his debut novel, titled Unfinished Business. Harper flies to New York where he will be the best man in his friend Lance's (Morris Chestnut) wedding to Mia (Monica Calhoun). Harper soon finds out that his friends have all received a copy of his book. His former friend and almost-lover Jordan (Nia Long) reads his book and soon realizes it is an autobiography. She begins to show Harper's friends part of the book and when it lands in the hands of Lance, a secret is revealed. This secret creates numerous isues and tests the friendship of Harper and Lance. It is up to Harper to make amends with all the people affected by his secret.