OBJECTIVES: Nationwide organized breast cancer screening programme was launched 2002 in Hungary for women between the age of 45-65 with a 2 years screening interval. The aim of the study is to analyse the within country inequalities of mammography coverage of the organized programme. METHODS: Data derive from the database of the National Health Insurance Fund Administration (OEP) containing routinely collected financial data. The study includes all the women aged 45-64 having either screening or diagnostic mammography before (2000-2001) and after (2002-2003 and 2004-2005) the introduction of organized screening. The regional inequalities are calculated for 19 counties and Budapest as the capital (altogether 20 items). Coverage is defined as the proportion of women resident who have had a mammogram at least once in the previous 2 years. RESULTS: National mammography coverage was 26,7 %, 54,6 % and 51,6 % in 2000-2001, 2002-2003 and 2004-2005 respectively. We found the highest coverage in 2000-2001 in counties having earlier pilot screening programme: county Tolna (59,2 %), county Jász-Nagykun-Szolnok (45,1 %), county Zala (39,5 %). After the introduction of nation-wide breast screening programme in 2002-2003 we found the highest coverage in the following counties: county Szabolcs-Szatmár-Bereg 70,8 %, county Borsod-Abaúj-Zemplén 64,4 %, county Veszprém 63,9 %. In 2004-2005, the following counties received the highest coverage: county Gyõr-Moson-Sopron (60,8 %), county Szabolcs-Szatmár-Bereg 58,1 % and county Vas 56,2 %. The ratio of coverage between the counties with the highest and lowest coverage was 3,5 (2000-2001), 2,6 (2002-2003) and 1,4 (2004-2005). CONCLUSION: We found significant within country differences in mammography coverage, however the gap between counties with lowest and highest coverage became smaller after the introduction of organized screening programme.