Human breast milk offers the optimal nutrition for all infants and have been widely used in biomonitoring programs to assess human exposure to lipophylic environmental contaminants such as polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF) and polychlorinated biphenyls (PCB). There are no previous reports from Turkey on chemically determined levels of PCDDs, PCDFs, and PCBs in human breast milk expressed as World Health Organization (WHO) toxic equivalents (TEQ). To get an overview of the levels of these contaminants in Turkish human milk, samples from 51 Turkish women living in the Ankara, Istanbul, Antalya, Kahramanmaras, and Afyon provinces were analyzed by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) throughout 2007. The mean concentrations of WHO(PCDD/F-)TEQ and WHO(PCB-)TEQ of all samples from the five regions were 7.5 and 3.1 pg g(-1) on a lipid basis, respectively. PCDD/F concentrations ranged between 0.78 and 29.3 pg WHO-TEQ g(-1) fat (1.7 and 36.2 pg WHO-TEQ g(-1) fat, respectively, including PCB). Of the five studied locations, the lowest levels of Sigma TEQs (PCDD/F + PCB) were found in the Afyon (6.8 pg WHO-TEQ g(-1) fat) and the highest in the Antalya (115.6 pg WHO-TEQ g(-1) fat) province. The results have been discussed in terms of regions and PCDD/F and PCBs for which analyses had been made. The mean levels of PCDD/Fs and PCBs in Turkish human milk are comparable to that found in other countries. (C) 2009 Elsevier Ltd. All rights reserved.