In this paper, a process for quantitation of residues of DOT (Dichloro-diphenyl trichloroethane) and its isomers, and HCH (Hexachlorohexane) in sediment was described. DOT and HCH are among the 13 groups of persistent organic pollutants (POPs) which must be phased-out of use and production according to the 2001 Stockholm Convention. The analytical procedure includes Soxhlet extraction with n-hexane, purification and fractioriation by Florisil packed column chromatography followed by quantitation using gas-chromatography with an electron capture detector (GC-ECD). The limit of detection (LOD) and limit of quantification (LOQ) of the process were estimated to be as low as 10 - 11 and 30 - 33 ng.g-1 (ppb), respectively. The accuracy of the process was checked through the participation in an Inter-laboratory comparison exercise with the IAEA-459 sediment sample. The Z-score for all the analyses was or