A novel catalyst, RhH(CO)(P(p-CF3Ph)(3))(3), was synthesized for homogeneous catalytic hydroformylation of olefins in supercritical carbon dioxide. The incorporation of p-(trifluoromethyl) groups to the conventional hydroformylation catalyst, HRhCO(PPh3)(3), provided enhanced solubility in supercritical carbon dioxide while maintaining catalyst activity and selectivity in the hydroformylation of 1-octene. The reaction rate showed a first-order dependency on the catalyst concentration. The total system pressure had no effect on either the reaction rate or selectivity. However, selectivity was found to depend on the catalyst concentration.