The objetive of this experiment was to determine the digestibility of protein (DP) and of energy (DE) of barley and its effect of inclusion in isocaloric diets on performance and economical viability for pigs during growing and finishing phases. Sixty Landrace x Large White barrows and gilts with 22.9 kg body weight were used during 90 experimental days. The experimental design was in complete randomized blocks with five treatments (0; 20; 40; 60 and 80%) of barley inclusion in isocaloric diets (as a total com and partial soybean replacement) by supplementation of soybean oil, with six replicates. The experimental unit was represented by pen (one barrow, one gilt). At the end of the experiment all pigs in each treatment were slaughtered and their carcasses evaluated. The means were for DP 85.64%, and for DE 3149 Kcal/kg. The performance and carcass characteristics data were not statistically significant (P greater-than-or-equal-to 0.01) among treatments. The results suggest that it is tecnically possible to include up to 80% of barley (total com replacement) on isocaloric basis for growing and finishing pigs. The best economical inclusion level of barley will be dependent on prices of corn, soybean meal, soybean oil and barley.