In 2 experimental studies, the authors hypothesized that the performance of altruistic citizenship behavior in a work setting would enhance the favorability of men's (but not women's) evaluations and recommendations, whereas the withholding of altruistic citizenship behavior would diminish the favorability of women's (but not men's) evaluations and recommendations. Results supported the authors' predictions. Together with the results of a 3rd study demonstrating that work-related altruism is thought to be less optional for women than for men, these results suggest that gender-stereotypic prescriptions regarding how men and women should behave result in different evaluative reactions to the same altruistic behavior, depending on the performer's sex.