In a recent experiment, Meston and Gorzalka (1995) [Behaviour, Research and Therapy, 33, 651-664] demonstrated a facilitatory effect of sympathetic activation, via acute exercise, on female sexual arousal. The present investigation was designed to examine the time course of this effect. Thirty-six sexually functional women participated in two experimental sessions in which they viewed a neutral film followed by an erotic film. In one of these sessions, Ss were exposed to 20 min of intense exercise (stationary cycling) prior to viewing the films. Subjective (self-report) and physiological (photoplethysmograph) sexual arousal were measured at either 5 min, 15 min, or 30 min post-exercise. Acute exercise marginally decreased vaginal pulse amplitude (VPA) and had no effect on vaginal blood volume (VBV) responses to an erotic film when measured 5 min post-exercise. At 15 min post-exercise, exercise significantly increased VPA and marginally increased VBV responses. At 30 min post-exercise, both VPA and VBV responses to an erotic film were marginally increased. Acute exercise had no significant effect on subjective perceptions of sexual arousal in any of the experimental conditions.