Aflatoxin M-1 (AFM(1)) levels were determined in 600 cheese samples (200 white, 200 kashar and 200 processed cheeses). The samples were collected from some provinces of Turkey and analysed between January 2001 and February 2002 in Bursa, Turkey. AFM(1) levels were determined by competitive enzyme-linked immunosorbent assay (ELISA) technique. The highest AFM(1) concentration was 800 ng/ka in kashar cheese. AFM(1) was detected in 30 (5 %) samples consisting of 10 white, 12 kashar and 8 processed cheese. Altogether, the AFM(1) levels in 6 of 600 (1 %) exceeded the legal limits of 250 ng/kg established by the Turkish Food Codex. (c) 2004 Elsevier Ltd. All rights reserved.