This paper presents adsorption isotherms for R-507A, which is a near azeotropic mixture of R-125 (pentafluoroethane) and R-143a (1, 1, 1-trifluoroethane) in equal mass fractions, on a Maxsorb III specimen of activated carbon in the temperature range of about (5 to 70) degrees C and pressure up to 15 bar. The data were obtained using the desorption method to an estimated precision of 5 % and fitted to three isotherm equations, namely, Dubinin-Astakhov, Langmuir, and Toth. The adsorption parameters were determined. Some peculiarities in isosteric heating behavior were observed.