Integrating general health initiatives into established occupational health programs may be an effective way of contributing more broadly to employee health. Objective assessment of the success of such initiatives is needed, but is often difficult to carry out because of their voluntary nature. A cohort of 24,586 wage employees, 35+ years of age and with 15+ years of prior employment, was established to assess morbidity and mortality outcomes relative to participation in an ongoing health initiative instituted in 1983. Outcomes were evaluated for employees who attended the seminar program (attendees), those who had clearance examinations, but did not take part in the program (withdrawals), and non-participants. At entry to follow-up, the prevalence of chronic illnesses including diabetes, obesity, and diseases of the circulatory system was lowest among non-participants and highest among withdrawals. During the follow-up period, the incidence of new disease conditions was similar between attendees and non-participants; however, overall mortality was significantly reduced among attendees after adjustment for explanatory factors including age, job grade, smoking history, alcohol intake, and body-mass-index (relative risk = 0.83; 95% confidence interval: 0.69-0.99) and was still marginally decreased when withdrawals were combined with attendees. Although self-selection cannot be ruled out as a contributing factor to the reduction in mortality risk among attendees, our findings indicate that offering health promotion activities in the context of an existing occupational health program may benefit overall employee health.