The detail kinetic study of 1-hexene hydroformylation using RhCl(AsPh3)(3) as a homogeneous catalyst has been investigated. The present kinetic study involves the effect of concentrations of 1-hexene and catalyst, partial pressures of CO and H-2, agitation speed, and temperature on the rate of hydroformylation. Additionally, the studies of deactivation of the catalyst RhCl(AsPh3)(3) with temperature have also been done. It was observed that the rates of hydroformylation reaction were increased on increasing the initial concentrations of 1-hexene, catalyst, and partial pressures of CO and H-2 at lower ranges. The activation energy was found to be 42.74 kJ/mol. A nonlinear semiempirical kinetic model was also developed to be the best fit with 11.6% error.