['The purpose of this study was to determine if a novel workplace stress management program, delivered either face-to-face or by self-help, would reduce illness and health services utilization among participants.', 'Five hundred one volunteers were randomly allocated to one of three groups: full intervention, which received assessment and personalized self-study feedback and was offered six face-to-face, small-group sessions; partial intervention, a self-help group that received assessment and personalized feedback by mail; and a wait-list control group. All participants completed questionnaires for stress, anxiety, and coping at the start of the study and 6 and 12 months later. Health reports were completed at 0, 3, 6, 9, and 12 months. A subsample of subjects who subscribed to a single health maintenance organization provided objectively recorded doctor visit data across the study year.', 'All three groups reported significant improvement in their stress, anxiety, and coping across the year. Full intervention participants showed a more rapid reduction in negative responses to stress than did participants from the other groups. Full-intervention subjects also reported fewer days of illness than subjects in the other groups. Objectively measured physician visits showed a large (34%) reduction in healthcare utilization for full intervention subjects in the HMO subsample.'] Does a novel stress and coping workplace program reduce illness and healthcare utilization?