Polystyrene-supported (R,S)-BINAPHOS-Rh complex was demonstrated to be applicable to the asymmetric hydroformylation of gaseous substrates in a non-solvent system: 3,3,3-trifluoropropene (2a) and (Z)-2-butene (2b) were converted into the corresponding branched aldehydes with 90% and 80%ee, respectively.