Fifty patients with prostate adenocarcinoma have been examined for p53 overexpression using immunochemistry, between 1993-1998 in Lütfi Kırdar Education and Research Hospital’s Pathology Department. Possible relations between p53 overexpression and different prognostic parameters such as type, histological grade, stage, vascular and perineural invasion have been evaluated. p53 overexpression have been encountered in 22% of all cases. Statistically significant relation between the intensity and distrubution of p53 staining was seen. Tumors in early stages and lower grades did not show p53 overexpression, wheras it was noticed that there is a statistically significant correlation between p53 overexpression and late stage and/or high grade tumors. There was no correlation with vascular and perineural invasion. In eight of 11 p53 positive cases there was nuclear staining in basal and secreting cells of benign neighbouring glands. Our findings support the view that p53 overexpression in prostate cancers are seen less than other organ cancers. p53 overexpression is correlated with Gleason’s grade and stage but is irrelevant with vascular and perineural invasion. Although p53 overexpression, evaluated as a single criterion is not a bad prognostic sign, its detection in latent and early prostate cancer may influence the therapy.