INTRODUCTION: The increasing prevalence of diabetes globally imposes financial burden on individuals, societies and health systems. However, not much is known about the treatment costs of diabetes and the coping mechanisms patients adopt in seeking care in the northern part of Ghana. In this study, we assessed the annual direct, indirect and intangible costs of diabetes mellitus care and related coping mechanisms of patients at the Tamale Teaching Hospital's Diabetic Clinic. METHODS: This was a descriptive cross-sectional cost-of-illness study conducted between June and August 2023 among 385 patients with diabetes in the Tamale Teaching Hospital of Ghana. Participants were selected by systematic random sampling. Direct medical costs (summation of cost of medications, investigations and admissions) and direct non-medical costs (cost of food and water, and transportation during hospital visits) together made up direct costs per patient per year. Indirect costs (lost wages as a result of illness or hospital visits) were estimated using the human capital approach. Intangible costs were analysed using a 5-point Likert Scale. Cost-coping mechanisms were obtained from the perspectives of the participants. RESULTS: The mean direct cost per person per year was found to be US59.70 (95% CI 126.70 to 193.04), with direct medical costs being on average US86.04 and direct non-medical costs being on average US5.59, while the mean indirect cost per person per year was US30.72. Average total cost of illness per person per year was found to be US90.44 (95% CI 248.64 to 334.70). The study participants often experienced intangible costs such as physical pain, easy fatiguability and diet changes as a result of diabetes and adopted a number of cost-coping mechanisms which included the use of savings, borrowing and reducing medication use. CONCLUSION: The costs incurred for care of diabetes mellitus in Northern Ghana are substantial, especially in view of Ghana's low minimum wage which was US.35 in 2023. This results in the adoption of adverse-cost-coping mechanisms that can drive families into further poverty with detrimental effects on the treatment of diabetes.