The separation of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ether (PBDE) congeners was evaluated on four capillary columns: 60 m x 0.25 mm i.d., 0.25 microm film thickness RTX-5MS and DB-XLB capillary columns, and 60 m x 0.18 mm i.d., 0.25 microm film thickness DB-XLB and DB-5MS capillary columns. Based on performance, capacity, and cost, the RTX-5MS (60 m x 0.25 mm i.d., 0.25 microm thickness) and the DB-XLB (60 m x 0.25 mm i.d., 0.25 microm film thickness) were selected for the analysis of human serum extracts by using gas chromatography/electron-capture detection. In contrast to previous studies, the oven temperature program affords the separation of congeners that are not separated by using other combinations of capillary columns, most notably PBDE-47 and PCB 180. In addition, the method enables determination of OCPs, PCBs, and PBDEs prevalent in a single extract of serum, which can lead to considerable time savings in the analysis of large number of samples collected for epidemiologic studies.