Abstract For the purpose of defining the distribution of breast diseases in Nigeria, a review of 671 cases seen in Ife over a 10 year period was undertaken. Twenty-six (3·9 per cent) of the patients were males. The frequency of breast diseases in this population was fibro-adenoma, 48 per cent; carcinoma, 21 per cent; breast abscess, 8·6 per cent; fibrocystic disease, 5·5 per cent; sclerosing adenosis. 5·4 per cent and gynaecomastia, 2·7 per cent. The other breast lesions were the same type of disease as documented in white patients. The most striking difference was the relatively high incidence of fibro-adenoma, especially in nulliparous adolescent females, while carcinoma and fibrocystic disease were fewer than expected. Breast carcinoma presented a decade earlier in Nigerian women and was usually advanced at presentation and of aggressive histological type. Of the breast carcinomas, 4·3 per cent were associated with pregnancy.