It's Greg Heffley's (Zachary Gordon) first day at middle school and he's keen to stand out from the crowd. With plenty of potential roles to be filled - sport champ, class clown, best dressed - Greg tries to find his niche, but his efforts to be cool are constantly thwarted by his dorky best friend Rowley (Robert Capron).
As Greg's popularity plummets, his life is made even more tiresome by a gang of bullies and his annoying older brother Rodrick (Devon Bostick). Plus, in his endless pursuit for acceptance, Greg fails to pick up on the attentions of smart school paper reporter Angie Steadman (Chloë Grace Moretz).
Based on the bestselling books by Jeff Kinney, school politics and gross-out humour take centre stage as the titular wimpy kid narrates the trials and tribulations of growing up.