The study sought to (1) model demographic and employment-related influences on behavioral health care utilization and cost; (2) model behavioral health care utilization and cost influences on general health care cost, job performance, and earnings; and (3) assess workplace-based health promotion's impact on these factors. Behavioral health care utilization was more common in employees who were female, over age 30, with below-median earnings, or with above-median general (non-behavioral) health care costs. Among employees utilizing behavioral health care, related costs were higher for employees with below-median earnings. Employees utilizing behavioral health care had higher general health care costs and received lower performance ratings than other employees. Health promotion participants were compared with a nonparticipant random sample matched on gender, age, and pre-intervention behavioral health care utilization. Among employees without pre-intervention behavioral health care, participants and nonparticipants did not differ in post-intervention utilization. Among employees utilizing behavioral health care adjusting for pre-intervention costs, participants had higher short-term post-intervention behavioral health care costs than nonparticipants.