Natural rubber (Hevea brasiliensis) is one of the major plantation crops of the state of Kerala in India and intercropping is practised during the initial gestation period of the crop. In this paper a tobit model was used to study the decision making behaviour of farmers in adoption and extent of adoption of intercropping in three regions of Kerala. The availability of family labour and the type of intercrops were found significant in explaining the adoption behavviour in all three regions. The perception of profitability of intercropping was also found to influence decision on adoption. The probability of adoption of intercropping was highest for three intercrops, banana (Musa spp.), cassava (Manihot esculenta) and pineapple (Ananas comosus). Targeting extension efforts to groups of farmers with available family labour and popularising selected intercrops may result in higher rates of adoption of intercropping in all three regions of the state.