Radio information is germane to cassava production. Past researches showed that radio stations disseminate agricultural information to farmers in Nigeria. Despite the effort of radio in this direction, cassava farmers have not been able to satisfy both local and international demands. However, this study investigated formats radio stations use to disseminate agricultural information to cassava farmers in Southwest, Nigeria. The study adopted multi-stage sampling technique for the selection of 593 cassava farmers who participated in this study. Findings revealed that radio stations used News (27%), Discussion (29.1%), Interview (19%) and Jingle formats (11.8%) to disseminate agricultural information to cassava farmers in Southwest, Nigeria. The study revealed that many cassava farmers' agricultural information needs were on loan facility (33.7%), availability of agricultural equipment (26.3%), availability of seedlings (17.5%), and climate and planting condition (15.6%). It was recommended that, radio stations should add formats such as lecture or straight talk, spot announcements, testimonial and entertainment to the formats already being used to disseminate agricultural information to cassava farmers. Radio stations should identify information needs to cassava farmers before disseminating agricultural information to them.