The study in which we investigated some sociodemographic and disease characteristics of 712 female patients with breast cancer, treated at Gülhane Military Medical Academy Medical Oncology Department, between 1992-2002 is a descriptive study. SSThe mean age of patients is 50.0$pm$ 12.1 years (median = 49). Of the patients, 54.5% were married, 10.5% were smoking and 3.5% were occasional drinkers at the time of first diagnosis. The proportion of patients without a history of pregnancy and breastfeeding were 6.4% and 11.6%, respectively. The frequency of female patients with a positive family history for breast cancer was 18.5%. The average of tumor size was 3.1 cm. Invasive ductal carcinomas and grade Il tumors were the most common findings regarding tumor histology, and grade. Of cases, 39.9% no metastatic lymph node was detected at the first diagnosis. The ostrogen and progesterone reseptör positivity were detected in 62.2%, and 51.3% of women, respectively. Bone was determined as the most common metastatic tissue at the time of first diagnosis. As a result, the patients in GATA study group were diagnosed at an earlier stage in comparison with the patients in developing countries, however it is estimated that the diagnosis was done at a later stage in comparison with developed countries.