Bullosis diabeticorum (BD), or diabetic bulla, is 1 of the cutaneous manifestations of diabetes mellitus, reported in 0.5% of people with diabeties in the United States, mostly in adult men who have had long-lasting and uncontrolled diabetes associated with diabetic peripheral neuropathy. However, BD in young children is a mostly unrecognized entity. We present a case of BD in a 3-year-old girl with type 1 diabetes mellitus who had been treated with insulin for 7 months prior to hospitalization. Dermatologic examination revealed a large, tense bulla filled with clear fluid and not associated with pain or pruritus, localized on the lateral margin of the right hand. A 4 mm punch biopsy was taken from the peripheral edge of the bulla under local anesthesia, and histology showed subepidermal bulla and sparse nonspecific infiltrate in the dermis; direct immunofluorescence was negative to complements C3, IgM, IgG and IgA. The particularities of the present case include the bulla in the absence of local trauma or any other complications of diabetes and associated with well-controlled type 1 diabetes. The diagnosis was certified by histology, direct immunofluorescence and clinical outcome. To the best of our knowledge, BD in young children has been previously reported in only 2 other publications.