Allison Scott (Katherine Heigl) is an up-and-coming entertainment journalist whose 24-year-old life is on the fast track. But it gets seriously derailed when a drunken one-nighter with slacker Ben Stone (Seth Rogen) results in an unwanted pregnancy. Faced with the prospect of going it alone or getting to know the baby's father, Allison decides to give the lovable doof a chance.

An overgrown kid who has no desire to settle down, Ben learns that he has a big decision to make with his kid's mom-to-be: will he hit the road or stay in the picture? Courting a woman you've just "Knocked Up," however, proves to be a little difficult when the two try their hands at dating. As they discover more about one another, it becomes painfully obvious that they're not the soul mates they'd hoped they might be!