Celiac crisis, an acute severe onset of celiac disease, is a rare and life-threatening manifestation. We report a 30-year-old woman with type 1 diabetes mellitus who arrived at our service with one-month history of severe acute watery diarrhea associated with nausea, vomiting, abdominal pain, and weight loss of 9 kg. The diagnostic hypothesis of celiac crisis was reached based on profuse diarrhea leading to dehydration, severe metabolic and electrolyte abnormalities, and subsequent improvement after introduction of a gluten-free diet.