The samples having complex matrices were analyzed for some heavy metal cations by using a thin layer chromatography/photodensitometry (TLC/PD) system, The rack samples mere dissolved by suitable methods. Nickel, Cobalt and Copper were dedected and analyzed by photodensitometric comparison of corresponding spots of samples with those of standards. The results of the same samples and standards a-ere compared with those obtained by atomic absorption measurements. Our results are comparable with the results of flame atomic absorption measurements. The precision of TLC method was calculated to be 9.4% as relative standard deviations depending on I? replicate measurements. The accuracy of TLC method was also controlled by analyzing a standard reference material (SRM) NIES No 2). The method exhibits about-2%-38% relative errors.