The state of development of methodology for measurement of polychlorinated biphenyls (PCBs) in ambient air and stationary sources was reviewed. The most promising method for ambient air measurements involves collection of PCBs on polyurethane foam, extraction with an organic solvent, removal of interferences by colum chromatography, and confirmation and analysis by electron-capture gas chromatography. Quantitation by perchlorination of PCBs to decachlorobipheny (DCB) is the most promising quantitation technique, but the procedure has not yet been perfected to the points are quantitatively converted to DCB. Perfection of this technique should allow for significant improvement in the quality of ambient PCB data being generated. Source and ambient methods differ mainly in sampling. Work on methodology for stationary sources is in the early stages of development and futher investigations are needed. The report contains 56 references.