Physical attractiveness is suggested to be an indicator of biological quality and therefore should be stable. However, transient factors such as gaze direction and facial expression affect facial attractiveness, suggesting it is not. We compared the relative importance of variation between faces with variation within faces due to facial expressions. 128 participants viewed photographs of 14 men and 16 women displaying the six basic facial expressions (anger, disgust, fear, happiness, sadness, surprise) and a neutral expression. Each rater saw each model only once with a randomly chosen expression. The effect of expressions on attractiveness was similar in male and female faces, although several expressions were not significantly different from each other. Identity was 2.2 times as important as emotion in attractiveness for both male and female pictures, suggesting that attractiveness is stable. Since the hard tissues of the face are unchangeable, people may still be able to perceive facial structure whatever expression the face is displaying, and still make attractiveness judgements based on structural cues.