Forty-two prostatic carcinoma patients with clinical stage A2, B or C underwent pelvic lymphadenectomy (limited node dissection) as a staging operation. The relationships among the presence of lymph node metastasis, tumor marker levels and histological findings of primary lesions were examined in 42 patients. Pelvic lymph node metastasis was noted in 18 (43%) of the 42 patients. The incidence of lymph node metastasis tended to be correlated with differentiation and Gleason's primary lesion sum. The preoperative PSA and PAP levels were significantly elevated in patients with positive lymph nodes for carcinoma than in those with negative lymph node for carcinoma. Patients with higher serum PSA (> or = 20 ng/ml) and PAP (> or = 10 ng/ml) levels were more frequently associated with lymph node metastasis. Thus, when serum PSA and PAP were markedly elevated before treatment in patients with prostatic carcinoma, they should be considered to have a potential of pelvic lymph node metastasis. Pelvic lymph node metastasis was observed in some cases even without high tumor marker levels, particularly those with poorly differentiated carcinoma.