Abstract: Sixteen crossbred beef steer (340±3.6 kg initial weight) were used in a 120 days feeding trial for to evaluate the interactions between Dry Distillers Grains plus Soluble (DDGS) and forage level in growing-finishing diets on productive performance of beef steers in feedlot. Two DDGS levels (0 vs. 15%) and two forage levels (35 vs. 65%) were evaluated in a 2x2 factorial arrangement of treatments. There were interaction between forage and DDGS level on final BW and Average Daily Gain (ADG) (p<0.05). In steers fed with low forage diets (35%) final BW and ADG increased with the DDGS addition (6.8 and 9.4%, respectively). No interactions between DDGS and forage level in intake Dry Matter (DMI) and Feed Efficiency (FE) were observed (p>0.05). DMI decreased with DDGS inclusion in both forage levels (p<0.05). Final BW, ADG, FE were improved by DDGS supplementation in cattle fed low forage diets.