The concentration and major sources of polychlorinated biphenyls (PCBs) were evaluated in the sediments from a special environmental protection area located near a transformer maintenance and repair facility (TMRF) in Ankara, Turkey. aPCB concentrations analyzed on Aroclor and congener basis (seven indicator congeners) ranged from 0.1 to 84.2 and 0.1 to 21.7 ng/g dry weight, respectively. Results show that higher total PCB concentrations were localized around one of the drainage channels of the TMRF. Identity and contribution of PCB sources were predicted using a chemical mass balance (CMB) based receptor model. The CMB model typically identified Aroclor 1260, the PCB mixture frequently used in transformers, as the major PCB source confirming the effect of the TMRF on the area. Poor prediction of some sample congener profiles suggest presence of environmental degradation mechanisms such as volatilization and differential solubilization of lower chlorinated congeners from sediments.