A rapid, economic, sensitive and reliable gas chromatographic method was developed and validated for the determination of residual Epichlorohydrin (ECH) in Pharmaceutical drug substances. This method utilized a Alltech AT-WAX GC column stationary phase consists of 100% polyethylene glycol, helium as carrier gas with flame ionization detection. The critical experimental parameters, such as, Column selection, injection volume and diluent were studied and optimized. The method was validated as per United States Pharmacopoeia (USP) and International Conference on Harmonization (ICH) guidelines in terms of detection limit (DL), quantitation limit (QL), linearity, precision, accuracy, ruggedness and robustness. A linear range from 0.6 to 3.4 μg/mL was obtained with the coefficient of determination (r2) 0.9985. The DL and QL of ECH were 0.15 μg/mL and 0.6 μg/mL, respectively. The recovery obtained for ECH was between 96.8% and 97.4%. This method was applied successfully to determine the content of Epichlorohydrin in several Pharmaceutical drug substances.