The screenplay by Gustin Nash focuses on a teenager who begins to dispense therapeutic advice and prescription drugs to the student body at his new high school in order to become popular.

[2][3] The son of a depressed but doting mother (Hope Davis) and a father who is serving time for tax evasion, wealthy teenager Charlie Bartlett (Anton Yelchin) — after being expelled from several private academies for various infractions — enrolls in a public school run by embittered alcoholic Principal Nathan Gardner (Robert Downey Jr.), who was formerly a history teacher.

He forms an alliance with school bully Murphy Bivens (Tyler Hilton) and offers him half the proceeds from the sale of a variety of prescription drugs Charlie obtains by feigning physical and emotional symptoms during sessions with different psychiatrists.

Charlie's social life noticeably improves as he gains the confidence and admiration of the student body and begins to date the principal's rebellious daughter, Susan (Kat Dennings).

Mr. Gardner takes up his old job as a history teacher again (and is now much happier), and Charlie finally gains the confidence to visit his father in prison (something he had felt uncomfortable about earlier in the film).

The film features four of the then Degrassi cast members as Charlie's fellow students: Jake Epstein (Craig Manning), Lauren Collins (Paige Michalchuk), Drake (Jimmy Brooks), and Ishan Davé (Linus).

The website's critical consensus reads: "With engaging performances marked by an inconsistent tone, Charlie Bartlett is a mixed bag of clever teen angst comedy and muddled storytelling.

[7] Stephen Holden of The New York Times wrote "If the attention span of Charlie Bartlett didn't wander here and there, the movie might have been a high school satire worthy of comparison with Alexander Payne's Election.

"[8] David Wiegand of the San Francisco Chronicle commented: "The script is adequate, although screenwriter Nash has created one distasteful character after another, and there's barely a ripple of relieving humor in the entire film ...

"[9] Jonathan Rosenbaum of the Chicago Reader called the film "a rebellious teen comedy that isn't as good or as radical as Pump Up the Volume, but still feels like a shot in the arm and is full of irreverent energy."

"[10] Darrell Hartmann of the New York Sun said, "John Poll's rebellious-teen comedy falls well below the high bar set by recent genre hits Juno and Superbad.