On behalf of the Nordic Council of Ministers’ Screening Group, NILU performed a study on short-, medium- and long-chain chlorinated paraffins (SCCPs, MCCPs, LCCPs) in urban air. Tire wear particles have been suggested to be a source for CPs and elevated urban concentrations of CPs. Air samples were here collected in three Nordic capitals (Finland, Iceland and Norway) in wintertime and in summertime. Higher concentrations of SCCPs and MCCPs were observed in wintertime than in summertime in Norway and Finland but no difference was observed in Iceland. Elevated concentrations of MCCPs and LCCPs were found at individual sites, but the concentrations at the urban sites were not consistently higher than at a background monitoring site. The results therefore showed no clear relationship to traffic. Instead, sources may be more diffusive and local sources seem to differ.