OBJECTIVES: In Mexico, the burden of disease from diabetes and related complications is very high.  According to epidemiological estimates, the burden will even increase more through time. However, there is minimal information on the disease management and usage of health care resources in the private sector, for diabetes. This study analyzes the treatment patterns and estimates the costs of treating diabetes and its complications from a private health care payer perspective. METHODS: Observational, retrospective, study of 1539 patients receiving care for diabetes.  Data for one year of follow up was extracted from a private insurance database, of patients 18 years of age and older. Analysis included treatment patterns details of diabetes and related complications, description of health care resources utilization and associated costs. RESULTS: The total average annual treatment cost per diabetic patient was in a range of $800 USD. The most common pharmaceutical scheme used to control glucose levels was metformin + sulfonylureas (34%) followed by metformin alone (22%). However, of the pharmaceutical expenditure only 26% accounted for glucose control, with the remaining designated mainly for treating related complications. The highest level of expenditure was due to hospitalizations, utilizing 40% of the total budget followed by pharmaceutical expenditures (17%). A total of 57.2% of patients had at least one complication and 17.7% two or more. The most frequent complication was ischemic heart disease, 32% of the patients. Diabetic nephropathy was the largest single contributor to the total cost of overall management of complications. CONCLUSIONS: In this study we analyzed the treatment patterns and resource use of treatment of diabetic patients in the private sector. This data is useful for planning of future resource allocation of diabetes care, given the increasing demand of health services in the area.