Pre-term infants frequently experience difficulties in attaining independent oral feeding, thus delaying the achievement of an adequate nutritional status and hospital discharge. The aim of this retrospective, single-centre, observational study was to investigate the effect of co-morbidities on the timing of the achievement of full oral feeding in pre-term infants. The neonatal and feeding data of 84 infants born at a gestational age of <32 weeks were collected, and the effect of co-morbidities on the achievement of feeding independence was evaluated using multiple linear regression analysis. The mean postmenstrual age at the time of the achievement of full oral feeding was 36.7 ± 3.68 weeks (range 33-53) weeks. The multiple linear regression analysis showed that a low birth weight, the occurrence of bronchopulmonary dysplasia, and the need for gastrointestinal surgical procedures were independently associated with a higher postmenstrual age at achievement of full oral feedings.