Purpose We assess the risk of systemic recurrence after retroperitoneal lymph node dissection for clinical stage I nonseminoma germ cell testis tumor based on predominance of embryonal carcinoma and/or vascular invasion in the orchiectomy specimen. Materials and Methods A total of 292 cases of clinical stage I nonseminoma germ cell testis tumor treated with retroperitoneal lymph node dissection from 1990 to 1995 were identified from the Indiana University database. A minimum of 2 years of followup was required for study entry. Review of the written pathological reports classified tumors as embryonal carcinoma predominant, when it was present at a level greater than any other histology, nonpredominant, when it was present but not as the main histological subtype, and absent. Vascular invasion was categorized as present or absent. Results Of the 292 cases 226 (77.4%) were pathological stage I and relapse rate after retroperitoneal lymph node dissection was 10.2%. Vascular invasion and embryonal carcinoma predominance in the orchiectomy specimen were predictors of relapse in this group. None of the 35 pathological stage II cases treated with adjuvant chemotherapy had relapse, whereas relapse occurred in 7 of 31 pathological stage II cases (22.6%) not treated with adjuvant chemotherapy. Conclusions Pathological stage I cases with predominant embryonal carcinoma and/or vascular invasion in the orchiectomy specimen have a higher probability of systemic recurrence after retroperitoneal lymph node dissection. Dissection alone still has a major therapeutic impact (77%) in patients with clinical stage I, pathological stage II nonseminoma germ cell testis tumor.