To define the cost-effectiveness of a back school program in industry, a controlled longitudinal field study was carried out in a Dutch bus company. The experimental group received a program consisting of information on back care, physical fitness, nutrition, stress, and relaxation. Objective data on absenteeism were collected and compared during a 6-year period for the control and experimental groups. Results showed that a tailor-made back school program reduced absenteeism by at least 5 days per year per employee, therefore being cost-effective to industry. A reduction was not observed in incidence, but in mean length of absenteeism. This effect turned out to be persistent during a 2-year period following the program.