Abstract: Objective:To evaluate the frequency and predictive factors of nipple involvement in a large contemporary cohort of pa-tients and to improve patient selection for the preservation of the nipple- areolar complex. Methods:This retrospective study re-viewed the medical charts of1,190 patients who underwent traditional mastectomy in Peking University People's Hospital between October2008and March 2014. Nipple involvement incidence was compared between the cases of clinically abnormal and clinically normal breasts. Other clinicopathological features and nipple status were analyzed to evaluate the association between these factors and occult nipple involvement. Univariate and multivariate analyses were conducted to identify predictive factors. Results:Nipple in -volvement was detected in6. 0% of the mastectomy specimens. Meanwhile, incidence was 40. 7% (22out of 54) in clinically abnormal nipple cases and 4. 3% (49out of 1,136 ) in clinically normal nipple cases ( χ 2=121 . 9, P<0. 001 ). Univariate analysis revealed that tumor lo -cation, tumor to nipple distance ( ≤ 2 and >2 cm), lymphovascular invasion, diameter (including carcinoma in situ; ≤ 3. 5 and >3. 5 cm), T stage, N stage, and TNM stage were associated with occult nipple involvement. By logistic regression analysis, tumor location, tumor to nipple distance, T stage, and N stage were determined to be the independent predictors of nipple involvement. Conclusion: Clinical abnormalities of the nipples are reliable and potent predictors of nipple pathology. The cases with peripheral tumor, T 1-T 2 stage, and N0-N 1 stage have lower probability of occult nipple involvement.