Human milk samples from 81 mothers living in seven selected localities of the Czech Republic collected in 1999-2000 were analyzed for PCDDs, PCDFs, and dioxin-like PCBs. Significant local differences in total WHO-TEQ values were observed (median ranges: 27.8-64.6 pg/g fat) with the highest level in Uherske Hradiste, but the highest PCDD-TEQ value was in Prague. Seven congeners (2,3,7,8-TCDD, 1,2,3,7,8-PeCDD, 2,3,4,7,8-PeCDF, and PCBs 118, 126, 156, and 157) cover about 90-94% of the total TEQ level. The non- and mono-ortho PCBs account for approximately 50-70% of the total TEQ levels in individual groups. The calculated median daily intake of the total TEQ for breast-fed infants ranged from 271 pg/kg b.w./day in Uherske Hradiste to 117 pg/kg b.w./day in Liberec and exceeded by about two orders of magnitude a tolerable daily intake (TDI) of 1-4 pg/kg b.w. recommended by the WHO. Our results confirmed significant local differences in the levels of dioxins and suggest that hot spot locations might exist within the country. (C) 2004 Elsevier B.V. All rights reserved.