The presence and concentrations of non-ortho-, mono-ortho-, and di-ortho-substituted PCB congeners in the polecat (n = 7), a member of the mustelid family, were investigated. PCBs were extracted with a Soxhlet apparatus. After cleanup the non-ortho-substituted PCB congeners were separated from the other PCBs by HPLC. Determinations were accomplished with GC-ECD or GC-MSD. Patterns of PCBs were examined in different organs and tissues: liver, kidney, muscle, anal gland secretion, mesenteric fat, and subcutaneous fat. Using a multivariate statistical method for data analysis (SIMCA), a significant difference of PCB patterns between anal gland secretion and the other organs and tissues was revealed. Lesser concentrations of congeners with seven and eight chlorine atoms in anal gland secretion were mainly responsible for this phenomenon. A more or less organ- and tissue-specific PCB pattern was observed in all animals. PCB patterns were not dependent on prey choice, which ranged from terrestrial (small rodents) to aquatic (amphibians). This finding implies that PCB patterns in the polecat seem to be controlled by metabolic processes rather than diet factors. The total concentration of PCBs (sum of 29 congeners) in polecats varies widely, two orders of magnitude, from 1 to 370 mug/g lipid. In some animals, PCBs exceeded the experimentally determined reproduction effect concentrations of mink and ferrets. Using the toxic equivalent approach, it was observed that planar PCB 126 accounts for 63 to 98% of the toxic equivalents. The results showed that juvenile animals contain greater PCB levels than adult males and females, which might be related to an increased elimination of PCBs in adult animals due to anal gland secretion. High concentrations of PCBs were observed in such secretion. A preliminary model for concentrations of PCBs in polecats including this effect is proposed.