Background: For the moment, scientific evaluation of programs on treatment of pregnancy-related pelvic girdle and/or low back pain after delivery is hardly available with only one study with a positive result, suggesting uncertainty about the optimal approach. Investigators draw particular attention to biomedical factors but there is growing evidence that biopsychosocial factors appear to be even more important as a basis of an intervention program. Methods: We studied the effectiveness of a tailor-made program with respect to biopsychosocial factors ( intervention group) in women with pregnancy-related pelvic girdle and/or low back pain versus usual care based on a pain contingent basis ( control group) shortly after delivery in a randomized controlled trial. Women with severe complaints shortly after delivery were selected from a longitudinal prospective cohort study ( n = 7526), aimed at pregnancy-related pelvic girdle and/or low back pain in the Netherlands. A concealed block randomization was performed after collecting baseline data. Researchers were blinded to treatment assignment. Outcomes were evaluated within the domains of the biopsychosocial approach. Primary outcome concerned limitations in activities (RDQ). Follow-up measurements were performed 12 weeks after delivery. Results: Since May 2001 until July 2003, 869 women out of the cohort made a request for treatment by a physiotherapist, 10 days after delivery. Because of a quick recovery in two weeks time, we included only 126 women three weeks after delivery. There was a statistically significant and clinically relevant difference in improvement on the primary outcome ( RDQ) between the two groups in favor of the experimental intervention. Conclusion: The results favored the hypotheses. Women's worries about their condition were major targets in the experimental intervention. The prognosis after delivery, especially in de first weeks, turned out to be favorable.