Introduction: The search for prognostic molecular markers in prostatic carcinoma is still ongoing. The present study was carried out to determine the degree of expression of periostin and P-cadherin by immunohistochemistry as well as nuclear morphometry as a predictor of clinical behavior in prostatic intraepithelial neoplasia (PIN) and prostatic carcinoma cases. Materials and methods: A total of 70 patients with prostatic lesions (20 patients with PIN, 40 patients with prostatic adenocarcinoma, and 10 cases patients with non-neoplastic prostatic inflammatory lesions as controls) from 2004 to 2009 who had not received radiation, hormonal therapy, or chemotherapy before surgery were studied. Representative tumor sections were stained immunohistochemically with antibodies against periostin and P-cadherin, and assessed semiquantitatively. The Gleason score and pathological tumor stage were recorded. The relationship between the expression of these proteins and clinicopathological parameters such as tumor nuclear grade, pathological stage, Gleason's score, and lymph node invasion was studied. All variables were correlated with clinical progression and disease-specific survival on univariate and multivariate analyses. Results: A statistically highly significant inverse relationship (P