Empire Online gives it 5 out of 5 stars and concludes, "Magnificent examination of the criminal mind and Cagney's finest moment." Slant Magazine discusses the psychological aspects.
Deep Focus Reviews says,
Cody’s awareness of his own psychological volatility transforms the character from an unsympathetic criminal into a tragic figure, more so because the burden paints him as a boy incapable of letting go of his attachment to his mother. White Heat so effectively bonds us to Cody’s emotional makeup—and yet, amazingly, does this without romanticizing his criminality—that the audience feels a sense of antagonism about Fallon and a strange sympathy toward Cody
Rotten Tomatoes has a positive critics consensus of 100%.