A signal-detection task was used to assess sex differences in emotional face recognition under conditions of uncertainty. Computer images of Ekman faces showing sad, angry, happy, and fearful emotional states were presented for 50ms to thirty-six men and thirty-seven women. All participants monitored for presentation of either happy, angry, or sad emotional expressions in three separate blocks. Happy faces were the most easily discriminated. Sad and angry expressions were most often mistaken for each other. Analyses of d^' values, hit rates, and reaction times all yielded similar results, with no sex differences for any of the measures.