During a 5-year period, 588 consecutive patients with nonseminomatous testicular germ cell cancer were included by 16 hospitals into the Swedish-Norwegian Testicular Cancer Project (SWENOTECA). A total of 370 (63%) had early clinical stages (CS1, CS1Mk+ and CS2A), and 345 (93%) of these patients underwent pathological staging (PS) by retroperitoneal lymph node dissection (RPLND). The overall clinical staging accuracy was 75%, with no significant difference between hospitals with low, medium or high patient accrual rate. Addition of bipedal lymphography did not improve the clinical staging accuracy compared to evaluation of the retroperitoneum by CT alone. Tumor serum markers before and close monitoring of the levels after orchiectomy gave valuable information regarding risk of retroperitoneal metastases. After a median follow-up period of 5 years 30 (13.8%) of 217 patients with PS1 disease relapsed, only 3 of them later than 18 months from the RPLND. Short orchiectomy to RPLND time interval, vascular invasion and absence of teratoma elements in the primary tumour were significant predictors of relapse in PS1 cases according to multivariate analysis. Unilateral RPLND was not associated with higher relapse rate than a bilateral procedure, but significantly reduced the risk of dry ejaculation after RPLND. None out of 122 PS2 patients who received adjuvant cisplatin-based chemotherapy after RPLND relapsed, despite the fact that 37 of them had only undergone a unilateral RPLND. Repeated CT examinations and most routine blood tests except serum alpha foeto protein (AFP), beta subunit of human chorionic gonadotropin (HCG) and lactate dehydrogenase (LD) may safely be omitted in the follow-up period for patients who have been pathologically staged with RPLND, provided that effective adjuvant chemotherapy has been given to the PS2 patients.