Release of the hormone cortisol represents a distress response to novel or stressful situations. Individual differences in such reactivity have been conceptualized as representing a relatively enduring, generalizable trait. In this study, cortisol responses to two experimentally manipulated "sexual" and "nonsexual" stressors were used to examine whether stress reactivity is related to sexual and nonsexual risk behavior in young adult males. Analyses were based on 150 males 18 to 25 years old; risk behavior was assessed in confidential, self-administered questionnaires. Analyses indicated that both stressors effectively elicited cortisol increases. Generalized reactivity, defined as a cortisol response to both stressors, was inversely associated with deviance (e.g., theft, substance use) and with two indicators of sexual risk taking (lifetime number of intercourse partners and frequency of condom use). Findings are discussed in terms of cross-situational consistency of stress responses, the utility of stress reactivity for understanding individual differences in risk taking, and the interpretive limitations imposed by study design.