Totally, 42/92 nonretired patients between 50 and 59 years of age were on sick leave for more than 6 months before total hip replacement for primary arthrosis. Reductions of these periods of sick leave to 6 months each would have meant a productive gain to society of 41,000-653,000 Swedish kronor per patient. The range in the estimate is due to the degree of causal relationship between preoperative and postoperative sick leave/early retirement.