An increasing number of patients with non-insulin-dependent diabetes mellitus (NIDDM) is presently being treated with insulin, some aggressively with intensified treatment schedules. However, there is little information on the ability of these patients to recover from insulin-induced hypoglycemia. We have, therefore, determined glucose recovery and counterregulatory hormone secretion in response to insulin-induced hypoglycemia in 10 NIDDM patients without autonomic neuropathy and in 6 age- and weight-matched normal controls. Recovery of plasma glucose concentration and hypoglycemia-induced increments of plasma concentrations of glucagon, epinephrine, norepinephrine, and HGH were similar in the NIDDM patients and the age- and weight-matched nondiabetic controls. It appears likely, therefore, that these NIDDM patients, if treated aggressively with insulin, may be at lesser risk for severe and prolonged hypoglycemia than insulin-dependent diabetic patients, particularly those with autonomic neuropathy or those treated with beta-adrenergic antagonists.