OBJECTIVE - To increase health-care professionals' awareness and knowledge of factitious illness by proxy, or Munchausen syndrome by proxy, in relatives of diabetic patients. RESEARCH DESIGN AND METHODS - A case report is described of a 14 old male who has a 6-yr history of diet-controlled diabetes mellitus, and a 6-mo history of reported spontaneous hypoglycemia. RESULTS - Neither diabetes nor spontaneous hypoglycemia was present in this child on objective testing. The child was subjected to inappropriate use of a strict diabetic diet and daily glucometer measurements for at least 8 yr. The father had convinced his son and health-care professionals of these diagnoses, in spite of evidence to the contrary. CONCLUSIONS - When confronted with history and clinical findings that contradict laboratory findings, health-care professionals should have a high index of suspicion for factitious illness and should pursue it aggressively with the help of legal services.