Two experiments were conducted to determine the effects of grazing height and supplementation levels of Marandu pastures on average daily gain (ADG), gain per hectare (GPH) and methane (CH 4) emissions during the wet season under continuous stocking by Nelore yearling bulls. Exp. 1: three grazing heights were evaluated: 15, 25 and 35 cm, combined with 0.3% of BW of a supplement (161 g crude protein (CP)/kg and 20.1 MJ gross energy (GE)/kg on dry matter basis (DMB)). Experimental design was completely randomized (three paddocks per treatment), and the effects were analyzed by polynomial orthogonal contrasts. Exp. 2: grazing heights were combined with decreasing supplementation levels as grazing heights increased: short height (15 cm) and high supplementation (0.6% of BW of a supplement: 142 g CP/kg and 18.9 MJ GE/kg on DMB) (SHHS); moderate height (25 cm) and moderate supplementation (0.3% of BW of a supplement: 161 g CP/kg and 20.1 MJ GE/kg on DMB) (MHMS) or tall height (35 cm) without supplementation) (THWS). Experimental design was completely randomized (three paddocks per treatment), and treatment means were compared by Tukey test (P < 0.05). In Exp. 1, ADG increased linearly (P = 0.02), and GPH decreased linearly (P = 0.0002) as grazing height increased. Methane emission was not affected (P = 0.64) by grazing height. In Exp. 2, ADG was not influenced (P = 0.14) by treatments. However, GPH was the greatest (P < 0.0001) for the SHHS treatment. In addition, CH 4 emissions were lower (P < 0.0001) in SHHS and MHMS bulls compared to THWS. The SHHS Abbreviations: ADF, acid detergent fiber (expressed inclusive of residual ash); aNDF, neutral detergent fiber (assayed with a heat stable amylase and expressed inclusive of residual ash); ADG, average daily gain; AU, animal unit; BW, body weight; CP, crude protein; DM, dry matter; DMB, dry matter basis; DMI, dry matter intake; GPH, gain per hectare; ha, hectare; GE, gross energy; IVOMD, in vitro organic matter digestibility; IVDMD, in vitro dry matter digestibility; MHMS, moderate height and moderate supplementation; ME, metabolizable energy; OM, organic matter; SHHS, short height and high supplementation; THWS, tall height without supplementation.