This study aimed to provide additional information on the influence of perinatal factors on fecal (f)-calprotectin values in preterm infants. Calprotectin was determined from the first spontaneous stool (analyzed on the Alegria device by using the enzyme-linked immunosorbent assay [ELISA] method) obtained from neonates at a mean age of 3.41 ± 2.44 days of life. We analyzed 114 subjects who had a body weight of 1847.67 ± 418.6 g and were born at a gestational age of 32.6 ± 2.43 weeks, without intestinal and other congenital anomalies or any diseases other than those related to premature birth. The values of f-calprotectin are in a positive correlation with female subjects, intrauterine growth restriction, significant ductus arteriosus, enteral feeding intolerance, postnatal prolonged use of broad-spectrum antibiotics, and values of bicarbonates (analyzed in a sample of capillary arterial blood). Measurement of f-calprotectin in the first 7 days after birth can help to early detect the intestinal distress or early staging of necrotizing enterocolitis in premature infants.