In patients with type 2 diabetes, the control of hyperglycemia is often difficult despite full doses of oral hypoglycemic agents and extremely large doses of insulin. These patients pose a major management problem. The authors therefore investigated whether insulin given as a subcutaneous continuous infusion of insulin (CSII) would result in an improvement in glucose homeostasis. Four patients with badly controlled type 2 diabetes, on treatment with extremely high doses of insulin and oral hypoglycemic agents, were started on CSII. All four patients had a marked improvement in plasma glucose concentrations with a corresponding fall in HbA1c levels. This improvement was associated with a marked fall in the insulin doses necessary to maintain adequate glucose homeostasis. Since HbA1c levels fell from levels that would be associated with diabetic complications to those at which complications are markedly reduced, we recommend that patients with type 2 diabetes uncontrolled on extremely high doses of insulin be given a trial of treatment with CSII.