In presenting and discussing a formula for determining the cost-effectiveness of health promotion programs, this paper addresses the following economic concepts: (f1) cause-specific years of life gained; (2) increased earnings; (3) program participant absenteeism, turn-over, and sick day utilization savings; (4) program cost; (5) cost per participant; and (6) benefit ratio of a prevention program. An example illustrating use of the formula is offered. (JD)