The compounding of rubber involves mixing of activator, co-activator, accelerator, antioxidant, filler, processing aid, vulcanizing agent, etc., to produce the rubber. The replacement of three of the above ingredients by rice-bran oil in the compounding of styrene butadiene rubber has been investigated. The higher fatty acids and phenols present in rice-bran oil act as co-activator and antioxidant, respectively, in the vulcanization process. Addition of this oil together with fillers, also meets the requirement of processing aid. The results obtained were compared with those obtained with reference mixes containing stearic acid, styrenated phenol and aromatic/napthenic oil in carbon-black and silica-filled systems. Evaluation of the cure characteristics of the mixes indicates that substitution of the above ingredients with rice-bran oil did not affect the cure properties. Vulcanizates containing the rice-bran oil also showed physical properties comparable to the reference mixes. Processability studies using a plasticorder also showed similar trends. Considering the fact that rice-bran oil is cheaper than other conventional oils used as processing aids in rubber compounding, this non-toxic natural oil can be advantageously used in rubber product manufacture.