The lambs production system in the South-European countries is characterised by producing light carcasses (< 13 kg) of young animals, less than 90 days old, and fed with the ewe milk and supplemented with concentrates. However, there is an increasing concern on the study of forage production system in growing lambs as a consequence of the interest in diversifying products and producing healthy and safe meat. When forage is included in the fattening diet a reduction of average daily gain is observed and carcasses have a lower degree of fatness, in comparison to the drylot system. The modification in the traditional type of carcass must be evaluated in order to assure that the final product meets the consumer demands. The objective of this experiment was to evaluate the effect of the lambs fattening system on the carcass characteristics and meat quality especially on the instrumental analysis traits as colour and texture.