There is potential for nonparticipation in health-promotion programs to impact on all overall success of these programs. The evidence on the relationship of participation of demographic and health characteristic is conflicting. The study presented here prospectively examined the relationship of personnel data and self-reported smoking, exercise, and dietary behavior to participation in the initial phase of a new health-promotion program. Compared with the total population, participants tended to be older and more educated, to be foreign-born and of Eastern ethnic origin, and to have more children. The participant population also tended to include more women, married individuals, and noncommissioned officers. A low smoking prevalence (17% of the participants), a high mean exercise rate (four times per week), and low weekly mean egg consumption (2.7) were observed among the program participants. These results indicate that this program preferentially enrolled people who already were committed to healthy lifestyles, and did not reach all segments of the work force equally.