Women in different phases of the menstrual cycle were compared to each other and to men in their responses to a social interaction stimulus: a videotape depicting a female nurse interacting with a hospitalized patient. Sex differences and cycle-phase differences were found for both affective and cognitive dimensions. Premenstrual women reported feeling more dominant, energetic, indifferent, negative, and somewhat more tense than women menstruating or women in the intermenstrual cycle phase. However, they did not differ from men in their affective ratings. Premenstrual women evaluated the nurse as less attractive than did men and they attributed greater responsibility for the nurse's behavior to the patient than men and intermenstrual women. Women in all groups evaluated the nurse as nicer and more pleasant, interesting, concerned and self-assured than did men. All women also felt more friendly toward the nurse and reported that they would be more comfortable asking her questions than the men did. The implications of these findings are discussed.