Aim: This study sought to determine the prevalence of diabetes mellitus (DM) among adult patients attending Specialist Hospital Gombe, Northern Nigeria. Materials and Methods: A 5-year (2010-2014) retrospective descriptive survey of cases of DM was conducted, using hospital record retrieved from the record (Institution). Diagnosed adult cases of DM were carefully identified and sorted from the general outpatient department morbidity register. Relevant data were then harvested on a specially designed pro forma/data collection template. Results: A total of 40,083 medical cases were counted out of which 2069 cases of DM were identified. This implies an overall prevalence rate of 5.16%. However, the yearly prevalence of the disease revealed as high as 12.55% in the year 2012 and a least value of 1.22% in the year 2010. Age-specific case count of the disease was found to be highest, 1288 (62.25%) within the highest age range of 65-75 while the lowest age range of 25-34 was least affected, 33 (1.60%). Overall, more females, 1491 (72.06%) suffered from the disease than males, 578 (27.94%). The sex difference was found to be significant (χ2 = 449.15521, P < 0.001). Furthermore, the case burden of the disease was found to be significantly (χ2 = 39.02524, P < 0.001) highest among individuals living in urban areas, 663 (80.38%) than those living in rural areas, 406 (19.62%). Conclusion: The disproportionately high case burdens of DM among females, urban dwellers and the aged are useful information for the design of targeted diabetes prevention programs by government and other stakeholders.