Compensation costs for work related low back pain (LBP) were discussed. Estimates of compensation costs for LBP obtained from workers' compensation data were considered. A survey of nine states showed that back injuries averaged 21 percent of all compensable work injuries. Liberty Mutual Insurance Company, the largest underwriter of workers' compensation insurance in the United States, reported that in 1980 they paid 217,441,000 dollars for compensable back pain. Costs per case were discussed. The best estimates have shown that the mean cost of compensable back pain is around 6000 dollars per case. Distribution of back pain costs was discussed. A few high cost LBP cases accounted for most of the costs. For example, a study of 191 LBP cases in 1976 showed that 25 percent of the cases accounted for 90 percent of the cost. The high cost cases usually involved prolonged hospitalization, surgery, litigation, and psychological problems. Other costs associated with LBP were discussed. These included medical treatment and rehabilitation provided at a factory dispensary, wages paid to other workers during work time interrupted by the injury, wages paid to the supervisor while managing the incident, wages paid to the injured worker between the time of injury and the time when workers' compensation payments begin, cost for paying full wages to a replacement worker, and wages paid to clerks and others for preparing and processing compensation application forms.