In the absence of dietary insufficiency, iron deficiency is usually caused by chronic blood loss or intestinal malabsorption. Celiac disease is one of the most common causes of intestinal malabsorption during childhood, and its association with insulin-dependent diabetes mellitus has been previously reported. Here the authors describe an otherwise asymptomatic diabetic adolescent boy with iron deficiency anemia that was not responsive to oral iron therapy. A diagnosis of celiac disease was made based on both anti-endomysial antibody titers and small intestinal biopsy. Institution of a gluten-free diet resulted in correction of the anemia. These observations emphasize the importance of considering a diagnosis of celiac disease in patients with nonresponsive iron deficiency anemia, particularly in the setting of insulin-dependent diabetes mellitus.