Diabetes Mellitus is an endocrine disorder due to deficiency or lack of insulin production leading to metabolic disorders of carbohydrate, fat and protein characterized by hypergly caemia, degenerating vascular changes and neuropathy. Mustapha (2010) Diabetes mellitus (DM) is a chronic multisystem disease related to abnormal insulin productions and impaired utilization of insulin or both. The study seeks to assess the level of knowledge of diabetes mellitus, dietary control and adherence among diabetic mellitus outpatients of University of Ilorin Teaching hospital, Ilorin Kwara State, Nigeria. The significance is to enlighten the victims of diabetes mellitus on the importance and cost effectiveness of diet management as a worthy alternative to expensive medication. This will enhance a healthy and productive life among diabetic patients. The study covers only diabetic outpatients attending University of Ilorin Teaching Hospital, Ilorin.