We tested a prediction that females' duration estimates of briefly-viewed male, but not female, photos would be modulated by attractiveness. Twenty-seven female participants viewed sequences of five stimuli of identical duration in which the first four were sine-wave gratings (Gabor discs) and the fifth was either the same sine-wave grating (control trials) or a photo of an attractive or unattractive male or female (test trials). After each sequence, participants had to reproduce the duration of the fifth stimulus. Results confirmed our prediction and showed that duration estimates of attractive male photos were significantly longer than corresponding estimates for unattractive male photos, while there was no significant difference in estimated duration for attractive and unattractive female photos. Our data show that unexpectedly viewing an attractive male affects time perception in females, and are the first demonstration that stimuli relevant to reproductive fitness, which engage the appetitive motivational system, can increase perceived duration.