One feeding trial and one digestion trial were conducted to compare hulless barley and corn in terms of their effects on pig performance, carcass traits, and nutrient digestibility. In the feeding trial, 32 crossbred pigs (Duroc x Landrace X Yorkshire), averaging 22.3 kg each, were randomly assigned to two treatments as follows: (1) a corn-soybean meal control diet, and (2) all the corn of the control diet replaced by hulless barley. In the digestion trial, eight crossbred gilts (Duroc X Landrace X Yorkshire), averaging 65.08 kg, were used to determine the digestibility of the diets. In the feeding trial, the average daily gain (ADG) of pigs fed the hulless barley diet was significantly higher than that of pigs fed the corn diet during the grower period, but the pigs fed the hulless barley diet were not significantly different in ADG from the pigs fed the corn diet during the finisher and overall periods. The daily feed intake of pigs fed the hulless barley diet was not significantly different from that of pigs fed the corn diet during the grower, finisher, and overall periods. The feed-to-gain ratio of pigs fed the hulless barley diet was not significantly different from that of pigs fed the com diet during the grower period, but the pigs fed the hulless barley diet required less feed per unit of gain than those fed the corn diet during the finisher and overall periods. The dressing percentage, carcass length, mean backfat thickness, and loin eye area of pigs fed the hulless barley diet were not significantly different from those of pigs fed the corn diet. In the digestion trial, the apparent digestion coefficients of dry matter and energy of pigs fed the hulless barley diet were not significantly different from those of pigs fed the corn diet. The coefficient for nitrogen tended to be lower for hulless barley than for corn (P < 0.07). From these results, hulless barley is concluded to be a potential alternative energy source for use in swine diets. (C) 2000 Elsevier Science B.V. All rights reserved.