Radio is a powerful mass medium having reach up to the unreached mainly because of low cost and its ability to be present and used everywhere, which suits to the purse of poor and marginal farmers of developing country like India. Researchers proved that it is one of the most effective media in promoting agriculture and development in rural areas, particularly as a tool for the delivery of quick information. A quasi-experimental study was designed to determine the effectiveness of the radio as an educational media to transfer agricultural information to farmers. A total of 63 subjects were selected randomly from two districts of Bihar. Based on scheduled programme on specific topic of interest to be broadcast by All India Radio Station, Darbhanga, a questionnaire was prepared for pre- and post-tests. The results indicated that the sample constituted 88.6 per cent male and 11.4 per cent female. 79.2 per cent of the farmers in the study were married; 48.9 per cent were illiterate and most were between 33-45 years old (48.9%). Most of the respondents had 6-10 members in their family (62.4%). Educational intervention through radio caused significant knowledge enhancement from 4.10 to 6.80 of a total 10, clearly indicating the effective role of radio to improve awareness of farmers. What is required is that an appropriate content, process, structure and system to be developed for such programmes

Keyword: Radio; Mass medium; Effective media; Educational media; All India Radio;