The influences of sex and lateralized visual hemispace bias in the judgment of the emotional valence of faces during a free viewing condition are evaluated. 73 subjects (aged 18 to 52 yr.) viewed videotaped facial expressions of emotion in normal and mirror-reversed orientation and classified each face as a positive, negative, or neutral expression. There was a significant interaction between the sex of the rater and the orientation of the face that influenced the proportion of correct classifications. Male and female perceivers did not differ in the accuracy of their affect judgments for faces viewed in normal orientation, whereas reversal of the orientation of the faces resulted in a significant enhancement of accuracy judgments for the males but not the females. The results suggest greater cerebral lateralization of perceptual processes in males.