Gender differences in anxiety, self-efficacy, activity tolerance, and adherence were assessed in 101 patients (80 males, 21 females) with coronary artery disease consecutively admitted to three phase II cardiac rehabilitation centers. The percentage of women in rehabilitation is 20% lower than anticipated based on coronary morbidity data. On admission to rehabilitation, men were significantly better able to tolerate physical activity, were less anxious, and perceived themselves as having greater efficacy in enduring exercise and activities of daily living than women. During the first month of rehabilitation, 24% of males and 33% of females missed 1 week or more of scheduled sessions. There were no significant differences in demographic or diagnostic characteristics between sexes.