This study aimed to determine cutoff levels for fecal calprotectin as a marker of intestinal distress in preterm neonates. A total of 126 infants born at a median gestational age of 33 weeks (range 25.7-35 weeks) were enrolled. Samples (n = 312) were collected weekly from the end of the first week of life until the end of the first month and if any gastrointestinal event occurred. Receiver operating characteristic curves analysis gave cutoff values of 363 microg/g (sensitivity 0.65, specificity 0.82) and 636 microg/g (sensitivity 0.72, specificity 0.95) for the development of mild or severe enteropathy.