We report on a 40-yr-old man with both primary enteropeptidase deficiency and celiac disease. He suffered from severe intestinal malabsorption and growth failure as a child. Enteropeptidase deficiency was found and pancreatic enzyme replacement therapy resulted in a growth spurt. Enteropeptidase levels in his intestinal mucosa and intraluminal fluid remained very low throughout childhood and early adult life. Celiac disease was confirmed by characteristic abnormalities in tests of intestinal function and in mucosal biopsies, which recovered when he instituted a gluten-free diet. He remains clinically intolerant to gluten as an adult. Enteropeptidase levels have remained abnormally low whether or not his intestinal mucosa has been normal in response to gluten restriction. Enteropeptidase levels have previously been shown to be normal in untreated celiac patients. The relationship between the two disorders remains unclear.