This study examined the influence of gender-related psychological characteristics and situational demands on physiological and affective responses to stressful tasks. While physiological and affective responses were monitored, 44 medical students (26 men, 18 women) performed an emotion-oriented speech task and an action-oriented speech in a counterbalanced design. Conventionally masculine instrumental and feminine expressive characteristics were measured using the Personal Attributes Questionnaire. Systolic blood pressure and respiratory reactions to the action-oriented task were positively associated with expressivity. Expressivity was also associated with greater subjective tension during the action-oriented task, and with perceptions of greater task difficulty. The results are consistent with the notion that physiological and affective stress reactions in men and women are determined in part by traditionally gender-related psychological characteristics, with greater reactions when the situational demands are not congruent with preferred modes of behavior.