Spectra of two isomers of the weakly bound complex OCS-CO2 are observed in the region of the CO2 nu(3) fundamental vibration (similar to 2349 cm(-1)), using. an infrared tunable diode laser to probe a pulsed supersonic slit jet expansion. Two bands are measured and analyzed for each isomer, the fundamental asymmetric stretch of the CO2 component and a combination band involving this fundamental plus the intermolecular out torsional mode. For one isomer, the corresponding torsional combination band is also detected in the OCS nu(1) stretching region (similar to 2060 cm(-1)). The resulting torsional frequencies are found to be 18.8 and 15.9 cm(-1) for isomers a and b of OCS-CO2, respectively This may be the first time that such a combination band is Observed for a higher-energy isomer of a weakly bound complex.