Quickly and accurately perceiving others' facial affect is paramount for successful social interaction. This work investigates the role of familiarity in helping us to interpret others' facial emotions. In Experiments 1 and 2, participants viewed several faces, some familiar and some novel, and judged how happy each face appeared. As predicted, results showed that familiar faces were perceived as happier than were novel faces. In Experiment 3, participants again viewed several faces, some familiar and some not, and rated the perceived anger or happiness of these faces. As expected, familiar faces were perceived as happier and less angry than were novel faces. Thus, these results suggest that familiarity is one cue we use to interpret the facial affect of others. Copyright © 2007 John Wiley & Sons, Ltd.