The accuracy of female perceivers on a face sex-categorization task was investigated as a function of perceivers' menstrual cycle and target facial qualities. Regularly ovulating female participants completed a sex-categorization task twice, once during ovulation (high fertility) and once during menstruation (low fertility). Perceivers made more errors in identifying male than female faces at both testing sessions. Fewer errors were made in identifying male targets rated high on masculinity, but only during periods of high fertility. For female targets accuracy was negatively associated with masculinity and positively associated with attractiveness ratings, at both high and low fertility testing sessions. Results are discussed in terms of adaptive person construal.