Aim: Premature babies are vulnerable to environmental stress factors mostly in the first weeks of life. During this time, supportive positioning, especially used all-around the baby, makes them feel better as if they are in utero. The aim of the study was to evaluate the effect of supportive positioning on weight gain, vital signs, feeding intolerance, duration of ventilation, duration of hospitalization and comfort scale scores of the premature babies in neonatal intensive care unit. Material and Methods: A total of 50 premature infants were recruited into the study randomly, 25 in the supported group and 25 in the control group. The babies in the supported group were nested with soft blankets and pillows as position material. There was no nesting or swaddling in the control group. Demographic findings, comfort scale scores, heart rate, respiratory rate and oxygen saturation of infants were recorded and compared. Results: Mean gestational weeks and birth weights of the supported and control groups were 32.9±2.5 (26-36) vs. 32.7±2.8 (26-36) weeks (p=0.791) and 1554±492 (680-2380) vs. 1772±439 (590-2375) g (p=0.105), respectively. Weight gain, ventilator days and days of hospitalization were similar in groups, however mean oxygen saturation and comfort scale scores showing deep sedation were higher in the supported group (p=0,024, p<0,001, respectively) after daily care. Conclusion: Although supportive positioning does not have an effect on duration of hospitalization, ventilation and weight gain, it has a positive effect on mean oxygen saturation and comfort scale scores of premature infants and recommended in newborn care.