Three female patients with a previously poorly controlled Insulin Dependent Diabetes Mellitus (IDDM), without evidence of cardiovascular, hepatic or renal dysfunction, developed generalized edema after a substantial increase in their insulin dosage. Edema resolved in 2-3 weeks, without specific therapy. Our patient's findings met the criteria of diagnosis of insulin edema. Insulin edema during IDDM is an uncommon complication of insulin therapy (1/400) and its pathogenesis is not clarified so far; it is a transient and self-limiting condition. The diagnosis is based on exclusion of all other major causes of edema.