A new congener specific method has been developed for extraction and quantitative determination of PCB contaminants of serum. After liquid-liquid extraction and chromatographic fractionation with Carbopack-C/florisil column, the analytes were identified and quantified utilizing gas chromatography/mass spectrometry (GC/MSD) using selected ion monitoring (SIM) technique. Recoveries of 35 non-planar PCB congeners (#18, 28, 31, 44, 49, 52, 60, 66, 74, 82, 87, 99, 101, 105, 110, 114, 118, 128, 138, 141, 146, 151, 153, 156, 157, 158, 167, 170, 171, 180, 183, 185, 187, 189 and 194) and 5 non-ortho (coplanar) congeners (#37, 77, 81, 126 and 169) from spiked serum were between 55-115%.