Cation-exchange resins in the acid form (Amberlyst-16, Wofatit KPS 200, Nafion, KU-2) have been tested as the acidic component of a catalyst system for the hydroformylation-acetalization tandem process. It has been shown that the hydroformylation of octene-1 in the presence of ethylene glycol and glycerol using a catalyst system comprising a rhodium complex, a phosphine ligand, and a solid acid leads to the formation of acetals with a yield of up to 99%.