This study assessed the diagnostic accuracy of fecal elastase 1 in chronic pancreatitis. Fifty-three healthy subjects, 44 patients with chronic pancreatitis (22 severe, 13 moderate, and 9 mild), and 43 patients with nonpancreatic digestive disease were studied. Elastase 1 concentration was determined on a small sample of feces using a commercially available kit. Fecal chymotrypsin was also measured. With a cutoff level of 190 microg/g, all healthy controls except one (98.1%), and the majority of patients with nonpancreatic digestive diseases (40 of 43; 93.0%) had elastase values above this limit. Among the 44 patients with chronic pancreatitis, 34 (77.3%) had pathological values: all 22 (100%) with severe disease, 10 of 13 (76.9%) with moderate disease and 2 of 9 (22.2%) with mild disease. Chymotrypsin values were pathological in 25 of 44 (56.8%) patients with chronic pancreatitis: 17 of 22 (77.2%) with severe pancreatitis, 7 of 13 (53.8%) with moderate pancreatitis, and 1 of 9 (11.1%) with mild disease. The specificity was 95.8% for elastase 1 and 85.4% for chymotrypsin. The difference both in sensitivity and specificity of the two enzymes was statistically significant (P < 0.05). Fecal elastase 1 has a high sensitivity, superior to that of fecal chymotrypsin, in the diagnosis of chronic pancreatitis. For its simplicity and rapidity, it could represent the tubeless test of choice in chronic pancreatitis.