The movie follows the story of Ben Stone, a carefree and whimsical man in his twenties who enjoys partying with his friends and working on a website that reviews movies. When he meets Alison Scott, a successful career woman, at a nightclub, they have a one-night stand that they both assume will be their last encounter.
However, Alison discovers she is pregnant and decides to keep the baby. She informs Ben, who initially seems uninterested in the pregnancy, but eventually decides to step up and be a responsible father. Despite their conflicting personalities, the two decide to try to make their relationship work for the sake of their unborn child.
Throughout the movie, Ben struggles to adapt to his newfound responsibility, navigating the challenges of adulthood while trying to maintain his carefree lifestyle, while Alison grapples with the implications of parenthood on her career and personal life. Despite the many obstacles they face, the couple eventually falls in love and decides to raise their child together.
The movie received critical acclaim for its honest portrayal of modern relationships and the challenges of parenting. It was a commercial success and became one of the highest-grossing comedies of 2007. Knocked Up also launched the careers of stars Seth Rogen and Katherine Heigl, who played Ben and Alison, respectively.