In this retrospective study, the authors assess the efficacy of combined insulin and oral hypoglycemic agents (OHAs) in controlling glycemic levels, as well as lipid levels and insulin requirements, in 48 patients with type II diabetes mellitus during a 1-year period. Thirty-two of these patients had secondary failure to an OHA (group 1). Sixteen patients (group 2) were taking high doses of insulin alone. Overall, 64.6% of all the patients responded to the combination therapy and insulin at 6 months. Response was defined as a decrease in hemoglobin A1c of more than 0.5%. At 12 months, 50% of these patients continued to respond to this regimen. No significant differences were seen in the patients' total cholesterol and triglyceride levels between responders and nonresponders in each group. After 1 year of combination OHA and insulin therapy, 50% of the patients showed a 21.4% reduction in their daily insulin dose.