Prostate cancer is the most common malignancy among males in the West. Any reduction in mortality would require early detection of cases in which curative treatment is possible. From 1994 through 1998, 105 patients with clinically localised T1-T2 tumours were operated via radical prostatectomy at Karolinska sjukhuset in Stockholm. Three patients were lost to follow-up. We obtained clinical data from patients' records and used pathologist reviews to characterise tumours regarding grade and histopathological stage. We used PSA in serum as a surrogate endpoint, with a value above 0.6 ng/ml designated as treatment failure. Outcome was examined with respect to tumour grade, histopathological stage and pre-operative PSA level. Altogether 22% of patients showed PSA failure during follow-up. No mortality due to prostate cancer was recorded. We found that both tumour grade and pre-operative serum PSA level correlated well with treatment failure (P < 0.01). Our findings illustrate the diagnostic difficulties involved, since a relatively large percentage of patients were registered for treatment failure shortly after radical prostatectomy.