This book looks at the effect of Radio on Da'wah activities using Okin Fm Radio station in Offa, Kwara State, north-central Nigeria as a case study. The work examines the concepts and characteristics of Radio, history and development, functions, Radio signs and codes. It also looks at the history of Radio broadcasting in Nigeria, and particularly the formation of Okin FM Radio. It equally examines the daily Da'wah programs on Okin FM, Ramadan programs featured on Okin FM Radio station. Besides, the author discusses therein the concepts and characteristics of Dacwah, meaning and attitudes of individual Dacwah worker, the principles of public Dacwah, qualities necessary for a good preacher (Daci'yah), as well as the methodology of Dacwah (preaching). The golden rules of communication for preachers, and Radio as a medium for mass preaching are all encapsulated in this humble work.It was concluded that the use of Radio particularly in the dissemination of religious activities has a tremendous advantage especially in the course of reaching out to the grass roots and the significance of media in social development of the society at large.