The hydrides CeCoSiH1.0 and CeCoGeH1.0 which crystallize like the parent antiferromagnetic compounds CeCoSi and CeCoGe in the tetragonal CeFeSi-type structure, have been investigated by specific heat and thermoelectric power measurements and H-1 nuclear magnetic resonance (NMR). CeCoSiH1.0 is an intermediate valence compound whereas CeCoGeH1.0 can be considered as a nearly trivalent cerium compound. This behaviour is corroborated by the occurrence of a slight broadening of the H-1 NMR signal in the sequence CeCoSiH1.0. CeCoGeH1.0. The band structure calculations performed on these hydrides reveal the existence of strong bonding Ce-H interaction, found to be larger in CeCoSiH1.0 than in CeCoGeH1.0.