Background: Breast self examination (BSE) is non invasive technique that women are able to practice to monitor any changes in their breasts. Breast cancer is one of the leading cause of cancer deaths in women worldwide so the early diagnosis & management of breast lesions is therefore important to reduce mortality .Objective of the study to assess the validity of breast self examination in detection of breast disease. Patients and method: The study was conducted in Breast Center, Radiology Department and Pathology Department in AL-Zahrawi Teaching Hospital over period between October 2005 to August 2006 in Mosul City. 113 selective patients presented with breast mass by self examination referred to combined examination (mammogram and sonogram) and the finding were compared with fine needle aspiration cytology. Result: 113 patients were examined by combined examination and histopathology biopsy showed 32 patients (28.31%)from total were normal, 68 patients (60.17%) were benign masses, the commonest benign tumor 26 patients (23.00%) were fibro adenomas, 5 patients (4.42%) were fibro/adenosis, 14 patients (12.38%) were breast abscess, 7 patients (6.19%) were breast cyst, 1 patient (0.88%) was lipoma, 15 patients (13.27%) were duct actasia and 13 patients (11.50%) were ductal carcinoma. Conclusion: Breast self examination is valuable in early detection of breast masses in addition to combined examination and fine needle aspiration and 66 patients (58.40%)of self examination was positive in triple test, periodic breast self examination is advisable to improve the mortality rate from breast cancer.