We investigated the effect of ice cream ingestion on blood glucose control in conventionally treated and intensively treated insulin-dependent (type I) diabetic patients. After the ingestion of 100 g of ice cream, plasma glucose excursions as measured by the peak increment (90± 30 mg/dL) and area under the curve (166±59 mg/dL X hour) were modest and not significantly different between the subgroups of intensively treated and conventionally treated diabetics. A small dose (3 to 5 units) of rapid-acting insulin given 30 minutes before ingestion of ice cream reduced the modest plasma glucose excursion. A modest amount of ice cream may be included in weight-maintaining diets of insulin-dependent diabetics. Small doses of rapid-acting insulin prevent any adverse effect of the ice cream on blood glucose control.