OBJECTIVES: Nationwide organized breast cancer program was introduced in 2002 in Hungary. The purpose of this study is to analyze the effect of breast cancer screening program on the number and ration of breast surgeries. METHODS: The data derived from the financial database of the National Health Insurance Fund Administration. We identified the patients with ICD codes and Diagnosis Related Groups (DRG). The study covers the five-year period between 2000-2004. We defined total mastectomy as the removal of preferably all breast tissue. Subtotal mastectomy (e.g. quadrantectomy) is defined as breast conserving surgery. We carried out the detailed analysis for the years 2000-2001, without nationwide organized screening program, and for the years 2002-2003 (first screening round) after the implementation of nationwide organized breast cancer screening program. RESULTS: The total number of breast surgeries was 7306 in 2000 and 7549 in 2001. After the introduction of the nation wide organized breast cancer screening program the total number of breast surgeries increased to 8531 in 2002 and 9140 in 2003. Compared to the values of 2000 as 100 %, the number of total mastectomies increased 107.8 % in 2002 and 109.6 %, while the number of subtotal mastectomies increased much more: 120.3 % in 2002 and 127.4 % in 2003. The ratio of total and subtotal mastectomies in 2000 was 46.2 % versus 53.8 %. By 2004 the proportion of total mastectomies decreased to 40.0 % and the proportion of subtotal mastectomies increased to 60%. The number of surgeries because of benign cases has also increased. CONCLUSIONS: The introduction of organized nationwide breast cancer screening program increased the total number of breast surgeries. Within the total number of breast surgeries decreased the proportion of total and increased the proportion of subtotal or breast conserving mastectomies.