Shaykh Uthman bin Foduye was a great revivalist whose reputation needs not to be elaborated, not only in Africa but other parts of the world. He was the founder of the famous Sokoto Caliphate and a prolific writer. Among his many books is the Kitabul Amri bil-Ma?aruf wan-Nahyi anil-Munkari in which he discussed issues concerning enjoining good deeds and forbidding bad deeds under Islamic Law. Therefore, this paper attempt to analyze the content of this book based on the following points: that enjoining good deeds and prohibiting bad deeds is mandatory in Qur?an, Sunnah and Ijma; that enjoining good deeds and forbidding bad deeds is not limited to leaders only but general responsibility of every Muslim that has the capacity to do it. That it is not allowed to condemn something that is based on different opinion of the scholars. In a situation whereby enjoining what is right and forbidding what is wrong requires the use of power then the task is limited to the authority. Lastly, recommendations and conclusion are provided.