Background: Body position affects the gastric emptying rate and hence the amount of gastric residue. Objective: This study aims to analyze the effect of the post-feeding position of preterm infants on gastric residue. Materials and Methods: This experimental study was conducted in the neonatal intensive care unit (NICU) of a university hospital (nonu University Turgut ozal Medical Center) in Eastern Turkey. The study included 40 preterm infants weighing less than 2,000g, who were fed orogastrically. The preterm infants were sequentially placed in four positions and were fed before each change of position. The infants were sequentially placed in the right lateral, left lateral, supine, and prone positions; their gastric residues were measured with a nasogastric tube. The gastric residue was recorded in percentages at 30, 60, 120, and 180 minutes. Ethical principles were applied in all phases of the study. Results: The lowest mean gastric residue level was observed in the right lateral position at 30 minutes (58.1612.71%) and 60 minutes (33.97 +/- 15.00%). The prone position showed the lowest mean gastric residue level (1.74 +/- 1.08%), followed by the right lateral (3.06 +/- 1.97%), supine (3.53 +/- 2.18%), and left lateral position (5.14 +/- 1.85%) at 120 minutes. The final measurements were taken at 180 minutes with the right lateral position showing the lowest mean gastric residue level (0.38 +/- 0.34%). Conclusion: The premature infants had similar lower levels of gastric residue in the right lateral and prone positions and higher levels of gastric residue in left lateral and supine positions. The gastric emptying rate was found to be highest in the right lateral position at 30, 60, and 180 minutes and in the prone position at 120 minutes.