From February 1981 until August 1984 20 patients (group A) with localized prostate cancer were treated by radical pelvic lymphadenectomy and direct 125-Iodine seed implantation. From September 1984 until January 1988 51 patients (group B) underwent a modified diagnostic pelvic lymphadenectomy: four weeks later the transperineal seed implantation, guided by rectal ultrasound, followed. The follow-up period in group A is 90 months (range 72 to 114), in group B 48 months (range 30 to 70). Nine patients of group A presented with a progression of disease, four died with/of disease. Ten patients of group B developed distant metastases, three of them presented with both, distant disease and local recurrence: one patient died of disease. The Kaplan-Meier five-year survival probability is 82.3% in group A, and 96.5% in group B: the disease-free survival 62.3% and 75.2% respectively. The probability of local control is 78% in group A and 93.5% in group B. In group A there is a higher incidence of complications compared to group B, in particular concerning edemas of the legs and the genital region. The rate of impotence after seed implantation is very low (2/57 = 3.5%).