Deficits in physical infrastructure, problems with availability of agricultural inputs and poor access to agriculture-related information are the major constraints on the growth of agricultural productivity in India. The productivity of castor in Karnataka during kharif season in the state is low and varies from 560 to 836 kg/ha. It is far below than that of national average (1653 kg/ha). In order to achieve higher productivity of castor, farmers need to access a wide range of information related to production technologies, post - harvest processes, remunerative markets, credit and weather. There are several organizations extensively using modern information technology in India to facilitate better communication between researchers, extension workers and their farmer clients to transfer technologies and information more cost effectively and the increasing penetration of mobile phone networks and handsets in India presents an opportunity to make useful information more widely available and plays a significant role in technology transfer. This study was conducted with castor farmers Chitradurga district, Karnataka and majority of the farmers perceived information on market price (75.5%), improved cultivars (73.9%) and weather forecast (71.0%) and the gain in knowledge scores showed differences between pre and post-dissemination of messages over mobile phones, which indicated that substantial improvement in knowledge, is possible with the use of mobile phones as source of knowledge access and they also felt that accessing information through mobile phone is easy and convenient.