The performance of a Rh/LaCoO3/Al2O3 catalyst has been investigated in the conversion of tar produced during biomass devolatilization into syngas using a dual fixed bed reactor set-up suitably developed. The effect of the addition of different levels of oxygen to the reaction mixture containing tarry compounds on the catalytic activity has been studied at 700 degrees C evaluating both the quality of the syngas produced and the extent of coke deposition on the catalyst surface. A comparison of the catalytic performance with that of catalysts containing Rh or LaCoO3 only has been done as well as with that of a conventional Ni-based sample. Coke deposition strongly decreases up to totally disappearing for 3000 ppm O-2 for Rh/LaCoO3/Al2O3 catalyst coupled to an increase in gas yield and a limited H-2 loss. H-2 and CO oxidations are conversely promoted by LaCoO3/Al2O3 catalyst in the presence of O-2.