Background: Polychlorinated Biphenyls (PCBs) are a group of toxins that are hydrophobic and lipophilic. Acute and chronical exposure through mother’s milk and food consumption can produce hyperactivity and disturbances in cognitive development in humans. Animal studies have shown inconsistent changes in behaviour and attention. More consistent findings of reductions in dopamine levels have also been found. This makes PCB exposure relevant for certain dopamine based diseases, such as Parkinson’s disease (PD) and Attention Deficit/Hyperactive Disorder (ADHD).Methods: Male outbreed Wistar Kyoto (WKY/NHsd) rats were exposed to 10 mg/kg PCBs 52, 153 or 180 dissolved in corn oil by gavage three times between PND 10 and 20. A control group were given pure corn oil. At postnatal day (PND) 35 the rats started testing on a RI EXT reinforcement schedule measuring activity, impulsivity and sustained attention. Results: Rats exposed to PCB 153 or 180 showed significantly less activity and impulsive behaviour than the controls and PCB 52 group. The PCB 153 and 180 groups also performed better on the sustained attention measure. No such results were found for the PCB 52 group. Discussion: It is suggested that the high dose of exposure to the highly chlorinated congeners PCB 153 and PCB 180 produced motor problems in the rats causing hypoactivity. The effect thus more resembles PD symptoms than ADHD. Further research is recommended on dose-response curves and animal models of the disorders investigating a possible genetic vulnerability factor.