The use of rice bran oil as a processing aid in styrene butadiene rubber has already been investigated in this laboratory. Based on the encouraging results obtained from this study, we thought also of trying this oil in polar rubbers like nitrile butadiene (NBR) and polychloroprene (CR). In this study an attempt is made to see whether rice bran oil which is a natural product, devoid of any toxic effects, can function as co-activator, antioxidant and as a processing aid in nitrile and as processing aid and antioxidant in polychloroprene rubber. The plasticizer, co-activator and antioxidant properties are compared with DOP, stearic acid and styrenated phenol, respectively, in the NBR vulcanization system and antioxidant, stearic acid and aromatic oil are replaced by the oil in the polychloroprene system. The mixes were evaluated for cure characteristics. Scorch time, cure time and the cure rate index values have shown that this oil can effectively replace plasticizer, co-activator and antioxidant form NBR mixes and processing aid and antioxidant form CR systems. The evaluation of mechanical properties and ageing studies of the vulcanisates also indicate that rice bran oil can be used as a multi-purpose additive in these rubbers.