In orally fed preterm infants, poor weight gain may be linked to low fecal pancreatic elastase-1 (FPE-1) activity, indicative of exocrine pancreatic insufficiency. The objective of this study was the retrospective assessment of the effect of exogenous digestive enzyme replacement by gavage in preterm infants with growth failure and low FPE-1 (<200 μg/g). We analyzed weight gain relative to baseline and caloric intake during 14-day periods before and after institution of digestive enzyme replacement containing 6000 U lipase and 240 U protease kg-1 d-1. Among 46 of 132 preterm infants < 1250g birth weight surviving to at least 14 days in whom FPE-1 was determined, 38 infants had low FPE-1 (< 200 μg/g), and 33 infants received exogenous digestive enzyme replacement. Average daily weight gain significantly increased from 14.4 [range 2.6-22.4] g kg-1 d-1to 17.4 [8.4-29.0] g kg-1 d-1 (P = 0.001), as did weight gain per kcal, from 0.08 [0.02-0.13] g kcal-1d-1 to 0.11 [0.05-0.18] g kcal-1 d-1.Conclusion: In preterm infants with signs and symptoms of exocrine pancreatic insufficiency, exogenous digestive enzyme replacement is associated with improved growth. What is Known: • Very preterm infants on full enteral nutrition may display growth failure linked to transient poor exocrine pancreatic function. • Porcine pancreatic enzymes covered with an acid-resistant coating are too large to pass the internal diameter of most gavage tubes used in very preterm infants. What is New: • Administration of a liquid formulation of acid-resistant microbial digestive enzymes in preterm infants with growth failure and low fecal pancreatic elastase-1 values was associated with improved weight gain. • Response to exogenous digestive enzyme replacement was associated with the prior extent of growth failure.