The thermal properties (thermal conductivity, thermal diffusivity, and specific heat capacity) of nitrite rubber (NBR)/poly(vinyl chloride) (PVC) blends were measured in the temperature range of 300-425 K. The incorporation of graphite into the NBR/PVC (30/70) matrix improved its thermal properties. Moreover, these properties slightly changed with the temperature. The thermal conductivity values of the prepared samples were compared with values modeled according to the Maxwell-Eucken, Cheng-Vachon, Lewis-Nielsen, geometric mean, and Agari-Uno models. The Agari-Uno model best predicted the effective thermal conductivity for the whole range of blend ratios and for the whole range of graphite contents in NBR/PVC (30/70)/graphite composites. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 116: 3171-3177, 2010