Background & Objectives: Breast Cancer is among the most common types of cancer in women which in case of early diagnosis and treatment can increase women’s chance of survival. This study was performed in two case and control groups.

 Methods: This case-control study which was based on hospital records was conducted on 303 breast cancer patients and 303 control women. The collected data were analyzed by SPSS using Chi-square.

 Results: The study revealed that there were significant differences between the cases and controls with regard to knowledge (p<0.001) and practice (p<0.001) of breast self-examination. 61% of the cases and 32% of the controls mentioned BSE as a necessary measure for the early diagnosis of breast cancer. 76% of the cases and 47% of the controls were not aware of the proper time for BSE (p<0.001). More than two-third of the subjects in each group did not know the proper time and the necessity of BSE in menopause and pregnant women and these was a statistically significant difference between two groups in this regard (p<0.001). Women in case group had done more frequently than controls (p<0.04). Moreover, the BSE intervals in two groups was statistically significant (p<0.01). There was also a significant difference between the reasons of refusing to do BSE in two groups (p<0.05). Subjects in neither group had regularly referred to a physician for examination and early diagnosis.

 Conclusion:�Since the knowledge and practice of women and their referring to a physician for breast examination is inadequate, it seems necessary to devise educational program about doing monthly BSE and hold educational courses to promote women’s knowledge concerning the early diagnosis of breast cancer as well as its appropriate and regular performance.