The effect of temperature on the interfacial tension for PS/PMMA, PS/PE, and PMMA/PE was measured using the imbedded fiber retraction method, interfacial tensions for PS/PMMA, PS/PE, and PMMA/PE were measured over temperature ranges of 160-250 degreesC, 140-220 degreesC. and 140-220 degreesC, respectively. The interfacial tension was found to follow a dependence of 3.6-0.013 T dyn/cm, 7.6-0.051 T dyn/cm and 11.8-0.017 T dyn/cm for PS/PMMA, PS/PE, and PMMA/PE, respectively. Comparison of the data with the mean field theory of Helfand and Sapse were made; however, a simple linear fit to the data described the temperature dependence in the experimental window as well as the predictions of the mean field theory.