Objective: Breast cancer is the most common type of cancer and the leading cause of cancer-related deaths in women in Turkey. This study presentsthe characteristics of patients registered in National Breast Cancer Registry Program of Turkish Federation of Breast Diseases Societies.Materials and Methods: The registry contains 242 variables under 10 categories and 699 questions. Patients were recorded (online and offline)from nationwide breast centers around Turkey.Results: Twenty-thousand patients were registered between May 2005 and April 2017 at 36 centers. After data cleaning, 19,503 women wereincluded in the study. The median age at diagnosis was 51 [14-97]; 17.2% were younger than 40 and 37.2% were premenopausal; 13.6% werenulliparous. Breast conserving surgery rate was 39.3%. Histopathology was invasive ductal cancer in 77%. Majority of patients had stage II cancer(48.3%). Estrogen, progesterone and HER-2 receptor positivity rates in invasive breast cancer were 72.5%, 62.5% and 21.8%, respectively. Themean tumor diameter was 2.5±1.7 cm. During the mean 51.6 months of follow-up, the local/regional and systemic recurrence rates were 3.7% and5.2%, respectively; five and 10-year overall survival rates were 86% and 76%.Conclusion: Despite increasing number of screening centers and free-of-charge mammography (ages 40 to 69) and mobile screening systems inrecent years, a significant portion of patients were diagnosed at advanced stage due to lack of breast cancer awareness. In contrast with the studypublished 5 years ago, there was a decrease in the rate of pre-menopausal women and an increase in the breast conserving surgery.