Kathryn Schroeder of FilmFracture writes: "Bad Teacher lives or dies on the performance by Cameron Diaz as Elizabeth, with a little help from her friends. Diaz takes the role of being a bad teacher to the limits, proving successfully that she does have what it takes to play a character who is hilariously deplorable. Diaz does not miss a single comedic beat throughout the entire film, working off of her co-stars with such detestable ease that the quick wit her character possesses is an enviable trait. In her moments of slight weakness, when she is doling out advice that is painstakingly honest yet refreshing to hear even if it involves swearing at a 12 year-old boy, Diaz manages to make Lucy almost someone you could learn to like. Almost. There will be no breaking down of the rough edged Elizabeth in the film, nor should you want there to be. She is perfect just as she is, being bad. "