The kinetics of the hydroformylation of high-molecular-weight cis-1,4-polybutadiene in the presence of HRh(CO)(PPh3)(3) and monochlorobenzene as a solvent were studied. The degree of conversion was examined by spectroscopic characterization with Fourier transform infrared and H-1-NMR analysis. According to the 2(4)-factorial experimental design, the temperature, catalyst concentration, and pressure appear to be significant factors for the hydroformylation of cis-1,4-polybutadiene. The kinetic studies indicated that the hydroformylation was first-order with respect to the catalyst and carbon-carbon double-bond concentrations and H-2/CO pressure (1:1 ratio). The effects of the H-2/CO ratio in the synthesis gas and added triphenyl phosphine were also studied. The apparent activation energy for the hydroformylation of cis-1,4-polybutadiene over the temperature range of 60-80 C was estimated to be 41 kJ/mol. (C) 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 854-869, 2004.