Biopsies of normoglandular prostate, of hyperplastic-atypical/preneoplastic prostate and of prostatic carcinomas of different grades of malignancy were stained according to the method described by Crocker and Ploton in order to demonstrate the silver stained nucleolar organizer regions (AgNORs). The AgNOR values per unit area of nucleus were compared to the nucleolar status. Increased grade of malignancy corresponds to an increase in the number of AgNORs per unit area of nucleus. Significant differences in the AgNOR values exist particularly in the subgroups of grade II of malignancy, as well as between grades G Ia through G IIa vs. G IIb through G III. Differentiating prostatic carcinoma into low and high states of malignancy is important not only for prognosis, but also for the therapy, since, when tumor-biological aspects are considered, a radical prostatectomy is no longer indicated in patients with highly malignant carcinomas.