In Nigeria, little attention has been paid to communicate and create awareness to teenagers about diabetes mellitus. Diabetes mellitus is a non-communicable disease which has become aserious health challenge globally affecting both the young and old. This study examined how effective communication can deepen teenagers‟ knowledge on diabetes mellitus menace with a view to effecting positive behaviour change and healthy living among the teenagers undergoing secondary education within the cosmopolitan area of Zaria. The study used a mixed method survey research design having both quantitative and qualitative tools whereby data and information were gathered from 325 respondents from the four selected schools (i.e. Government Secondary School Jama‟a, Government Secondary School Muchia, Model Learning Secondary School and Vital Years Secondary School). This was supported byHealth Action Process Approach (HAPA) and theory of Health Promotion Model (HPM) that are based on individual characteristics and experiences, behavior-specific cognitions and effect, and behavioral outcomes. Findings of the study showed that there is low level of awareness about diabetes mellitus among the respondents in the selected schools, especially the public schools. The private schools showed more knowledge about diabetes mellitus than the public schools. Various communication channels, including social media platforms, mass media, parental counsel, health talk and religious institutions were noted by the respondents as reliable for effective communication of diabetes mellitus. These identified tools of communicating diabetes mellitus are at present underutilized in the study area. Another significant finding is that diabetes mellitus is not included as a subject of discourse in secondary school curriculum. Other constraints to effective communication of diabetes mellitus, including inaccessibility of internet in the schools, lack of health awareness programmes, wrong use of communication channels and insufficient information about diabetes mellitus were also noted by the respondents. It is, therefore, suggested that there is need to improve awareness creation on diabetes mellitus through such channels as creation of school counseling unit, establishment of drama clubs and regular health talk symposia, The gap noted on the awareness level of diabetes mellitus between the private and public schools can be reduced through the promotion of literary and debating society activities, intra and inter school competitions, seminars and hospital visitations. It is thus imperative that teenagers need to be encouraged to participate actively in communication design and implementation of diabetes mellitus programme to curb the menace of its spread in the society.