Studies were carried out to determine the effect of beta-glucanase supplementation to hulless barley-soybean meal (HB+SBM) or wheat-soybean meal (W+SBM) diets on the digestibilities of GE, CP, beta-glucans, and amino acids. Twelve barrows, average BW 7.3 kg, were fitted with a simple T-cannula at the distal ileum, approximately 5 cm from the ileo-cecal sphincter. After a 7-d recuperation period, six pigs were allotted to each dietary treatment according to a two-period crossover design. Both diets were formulated to contain 20% CP without and with supplementation of .2% beta-glucanase. beta-glucanase refers to a mixture of enzymes with endo- and exo-beta-glucanase and beta-glucosidase activities. Chromic oxide was included as a digestibility marker. The pigs were fed three times daily at 0800, 1600, and 2400 and the daily allowance was offered at a rate of 5% of BW. Each experimental period lasted 9 d. Feces were collected for 48 h on d 6 and 7 and ileal digesta for a total of 24 h on d 8 and 9. beta-glucanase supplementation to the HB+SBM diet increased (P < .05 or P < .01) the ileal digestibilities of GE, CP, beta-glucans, and the majority of the amino acids and the fecal digestibilities of GE, CP, and all amino acids measured; the fecal digestibility of beta-glucans in the HB+SBM diet was not affected by beta-glucanase supplementation. There was no effect (P > .05) of beta-glucanase supplementation to the W+SBM diet on the ileal digestibilities of any criteria measured except for beta-glucans (P < .05). The supplementation of beta-glucanase to the W+SBM diet increased (P < .05) the fecal digestibility of energy but not (P > .05) the other criteria measured.