Non-medical factors influencing treatment choices in prostate cancer are not well understood. We carried out a population-based study to obtain information on the management of prostate cancer patients. Our study population consisted of 1000 men diagnosed during 1995 from five French cancer registries. We looked at the main treatments performed in the year following diagnosis. Multivariate analysis was used to describe the determinants of the various treatment choices, simultaneously taking into account medical and non-medical factors. The probability of treatment by radical prostatectomy (RP) was 3 times higher in the Tarn area, whereas in the Calvados area the probability of treatment by radiotherapy was almost 6 times higher. The private sector favoured radical prostatectomy and hormonal therapy. In France, as in other developed countries, the initial treatment of prostate cancer varies greatly according to non-medical factors. This type of investigation, if carried out regularly, would make it possible to evaluate changes in practice patterns.