cis-1,4-Polyisoprene is pyrolyzed under an inert atmosphere at different temperature ranges by using differential thermal analysis and pyrolysis-gas chromatography. Fourier transform-infrared is used for investigating the pyrolysis residue. The pyrolyzed gaseous products are analyzed by gas chromatography. The effect of temperature range on the relative yields of the major decomposition products is studied. Based on these data, the thermal degradation mechanism of cis-1,4-polyisoprene is also proposed. (C) 2002 Elsevier Science Ltd All rights reserved.