The goal was to evaluate the chemical composition and fermentation pattern of elephant grass (Pennisetum purpureum Schum. cv. Roxo) silage with different levels of soybean hulls or rice bran. Two trials were conducted, comprising of a completely randomized design, with four replicates each. Treatments consisted on the addition of 0%, 5%, 10%, and 15% of soybean hulls or rice bran to unwilted green elephant grass forage. Large PVC silos were used adopting a density of 600 kg of green mass m-3. The silos were opened 40 days after ensiling. The results revealed that the inclusion of 10% soybean hulls increased elephant grass forage dry matter (DM) content to 31%, but did not alter the water soluble carbohydrate (WSC) content or buffering capacity. The resultant silages exhibited good fermentation patterns in terms of pH (less than 3.97) and NH3-N (4.07% total N) levels. The inclusion of rice bran increased both DM and WSC content in the forage, improving the fermentation pattern of silages (P < 0.05). This too was verified by a pH lower than 3.92 and a maximum NH3-N of 4.23% of the total N. The inclusion of 10% rice bran to the elephant grass improved the nutritional value of the forage to be ensiled and, hence, of the produced silage.