The study was conducted to investigate the knowledge, behavior and application of a group of women towards breast cancer. The universe of the descriptive research was composed of 35-years old women and over (280 women) who had five social facility in a municipality subsidiary to city in Gaziantep between October-November 2014. The sample selection was not made and entire universe was included in the research. The research was conducted with a total of 233 women. The data collection tool was constructed by searching the related literature and the questionnaire was composed of questions about socio-demographic variables of women (9 questions) and information, behaviors and applications about breast cancer (20 questions). Necessary institutional permissions were obtained for the study. SSPS 18 package program was used to evaluate the obtained data. Number, frequency, percentage, mean, Pearson Chi-Square tests were used for statistical calculations. It was determined in the study that the average age of women is 43.00 ± 7.37; 39.5% were primary school graduates; 88.4% were married, 27.5% were using cigarettes; 26.2% had breast cancer stories in their family; 28.8% of them received information about breast cancer from health personnel; 18.9% of them were in the bloodstream and 13.9% expressed in the first rank in breast cancer symptoms in breast mass detection; 48.5% did not know how to do the breast self examination; 21.5% of those who are involved in the breast self examination do this once a month; 13.7% made the breast self examination at the right time; 25.3% believed that the breast self examination needed it. It was found that the difference between the believing the breast self examination to be necessary according to the timing and frequency of the breast self examination by women was statistically significant (p<0.05). Although women found their knowledge of breast cancer to be adequate, they did not make early diagnosis and it was determined that the rate of believing that breast self examination was not as desirable as these applications. It was determined that there is large opening between believing breast self examination which is an effective diagnostic method for breast cancer is necessary, and application of breast self examination at the right time and frequency.