The interfacial tension of poly(p-phenylene sulfide) (PPS) with various thermoplastics of different composition and polarity has been carried out using the breaking thread and pendent drop methods. The value of the polyethylene (PE)/PPS interfacial tension is found to be intermediate between PE/polysulfone and PE/polycarbonate. The highest interfacial tension for PPS found in the systems studied was with polyamide-6 followed by PE. The lowest values were with polysulfone followed by polystyrene. The effects of small additions of polysulfone and polystyrene in PPS on interfacial tension is studied with various thermoplastics.