The objective of this study was to determine whether sunflower hulls (SFH) could be used as a partial replacement for barley silage in diets for finishing lambs. Eighteen Canadian Arcott wether lambs were randomly assigned to 1 of 3 treatments: 0SFH (60% barley grain, 30% barley silage and 10% lamb mineral pellet), 7.5SFH (60% barley grain, 22.5% barley silage and 10% lamb mineral pellet) and 15SFH (60% barley grain, 15% barley silage and 10% lamb mineral pellet). The lambs were weighed on 2 consecutive days at the start and end of the 25-d feeding period. Total fecal collection was performed from d 21 to 24, and behavior was monitored on d 25. Samples of feed and refusals were analyzed to evaluate the sorting index. Data were analyzed as a completely randomized design using mixed model of SAS. Dry matter intake was not affected (P = 0.32) averaging 1.4 kg/d but ADG increased (quadratic, P = 0.03) from 160 g/d for 0SFH to 215 g/d for 7.5SFH followed by a decrease for 15SFH (143 g/d). Sheep fed 15SFH sorted against particles retained on the 8 mm sieve (P < 0.01), tended to sort for particles retained on the 1.18 mm sieve (P = 0.09) and sorted for particles retained on the pan (P < 0.05) showing there was preference for the 19mm, 1.8mm and < 1.8mm particles in the diet. There was no difference in time spent ruminating or eating between the treatments (P > 0.1) but 15SFH spent less time drinking than lambs fed 0SFH (P = 0.03). Apparent total-tract digestibility was not affected by treatments (P > 0.1) with DM, CP, NDF, and ADF digestibility averaging 72.7, 71.6, 45.8, and 39.7%, respectively. The data in this study indicate that sunflower hulls can be used as a partial replacement for barley silage without negatively affecting DMI, G:F, feeding behavior and digestibility.