Abstract: In this study samples of four species of the most consumed fishes (Sefid, koli, kilca and kafal fish) were analyzed for concentrations of Chlorobenzilate (organochlorine pesticides). Fish were captured using electric fishing on four sites (Chalous and Babolsar city and Khazar Abad and Miankaleh regions) in Mazandaran provinces of Iran. Quantitative determination of the Chlorobenzilate was performed by gas chromatography electron-capture detection (GC–ECD). Samples contained detectable concentrations of Chlorobenzilate but at concentrations below the maximum residue limit (MRL). No different found between kinds of fishes in each sites about Chlorobenzilate concentrations but there are two groups of sites that were significantly different from one another in terms of Chlorobenzilate concentrations. According to insecticides analyzed in four kinds of fishes the Kafal in the hunting region of Khazar abad had greatest amount of 0.038 PPM. Kilca from Babolsar had the highest amount of Chlorobenzilate, 0.035 PPM (P< 0.05). In the case of Sefid and Koli fishes in regions, significant difference was not seen. It is necessary to mention that no research has so far been done to be a criterion for comparison in this area sites. However, the concentrations of Chlorobenzilate residues in the muscle were found to be lower than the FAO/WHO recommended permissible and should not be public concern among peoples in Mazandaran province.