Methods of diagnosis in metastatic disease of patients with prostatic cancer are reported. There is a high rate of inaccuracy in lymphography. In 23 patients the technique of transperitoneal fine needle aspiration biopsy of retroperitoneal lymph nodes after lymphography was used. In 8 patients malignant cells were found while lymphography showed metastases only in 4 cases. In these 8 cases a staging-operation was not indicated.