Plasma or serum samples of 147 individuals [human] from the general population of a continental town in Croatia (Yugoslavia) were analyzed for chlorinated hydrocarbons in 1975. The compounds were determined by gas chromatography and identified by comparing their retention times with those of known standards. All samples contained p,p''-DDE; mean concentration was 35.3 ppb. Only 20 samples contained p,p''-DDT; mean concentration was 22.7 ppb. Concentrations of .alpha.-BHC, lindane and p,p''-TDE were 3.25, 4.09 and 11.6 ppb, respectively.