The heterogenized versions of [RuCl2(PPh3)(3)] and [{RuCl2(TPPMS)(2)}(2)] were prepared and applied in the selective hydrogenation of alpha,beta-unsaturated aldehydes. Depending on the conditions the above heterogenized catalysts could hydrogenate selectively either the C=O or the C=C bonds, similar to the results obtained in aqueous biphasic systems. Meanwhile the heterogenized catalysts show all the advantages that we can expect from a heterogeneous catalyst: good performance, easy separation, and the possibility of recycling. The effect of H-2 pressure on the selectivity was also studied. (C) 2004 Elsevier Inc. All rights reserved.