BACKGROUND Measurement of pancreatic exocrine function and steatorrhea in chronic pancreatitis in the clinical setting has not received much attention. OBJECTIVE To assess pancreatic exocrine function and fecal fat excretion in a cohort of patients with chronic pancreatitis. METHODS Stool elastase1 levels were measured in 101 patients using polyclonal ELISA and acid steatocrit was measured in 86 chronic pancreatitis patients. Associations with etiology, clinical and radiological features, and diabetic status were examined. RESULTS Low pancreatic stool elastase1 (<200 microg/g stool) was observed in two-thirds of chronic pancreatitis patients and correlated with ductal dilatation, pancreatic atrophy and calcification (p<0.05). Diabetes was more prevalent in chronic pancreatitis patients with low elastase1 (p=0.045). There was no difference in mean acid steatocrit between diabetics and non-diabetics (p=0.069). Elastase1 levels had a negative correlation with acid steatocrit (r=-0.606, p<0.001), and a positive correlation (r=0.412) with body mass index (p=0.013). Fifty-three percent of chronic pancreatitis patients with normal BMI had low elastase1. CONCLUSIONS Fecal elastase1 levels correlated with fecal fat excretion and BMI. Fecal elastase1 estimation may be helpful in early detection of malabsorption in chronic pancreatitis.