Despite the essential role of insulin in the management of patients with diabetes mellitus type 1, insulin use can cause a variety of adverse effects, such as hypoglycemia and weight gain. Herein, we describe an adolescent girl with type 1 diabetes mellitus diagnosed one year ago, who presented with edema of the lower extremities approximately two weeks after an increase in the insulin dose; other causes of edema were excluded. Spontaneous recovery was observed in the patient.