Hybrid monoliths able to bind metal species were prepared by sol-gel method using different catalysts and solvents. Starting materials were the "double" thioureas 1,4-[(EtO)(3)Si(CH2)(3)NHC(S)NH](2)(C6H4) (Siphen) and 1,12-[(EtO)(3)Si(CH2)(3) NHC(S)NH](2)(C12H24) (SiC12). Rh(I) and Pd(II) species were anchored through sulphur co-ordination on the surface of the monoliths obtained from Siphen. In the case of Rh(I), anchored metal complexes were spectroscopically identified by FTIR microspectrometry. The metal leaching was determined in the hydroformylation (Rh) and hydrogenation (Pd) of styrene. The metal species present in reaction solutions were quantified using plasma atomic emission spectrometry. (C) 2003 Elsevier Science B.V. All rights reserved.