Breast cancer accounts for about 26% of all newly diagnosed cancers in women aged 20 to 59 years. As part of a basic program for cancer control, the present cross sectional descriptive study was conducted with the objective of determining the epidemiology of breast cancer in Ardabil province during 2003-2010. Necessary information on 469 recorded cases of breast cancer in the registry were collected by check list from patient's files and then analyzed by statistical methods with SPSS.16 software. Some 455 of the patients (97%) were female, 329 (70.1%) residing in Ardabil. The mean age was 46.8 ± 13.6 and most were in the age group of 40 - 60. The most prevalent pathologic form was infiltrative ductal carcinoma with 316 cases (67.4%), the largest proportion being grade II (30.6%), but very many belonged to grades III and IV (40.5%). Breast cancer in Ardabil province appeared to slightly increase over the period studied. The results were similar to other places in Asia. With regard to this, more widespread studies are required to determine factors influencing the prevalence at low age and also how to promote early detection.