BACKGROUND Scheduled interval feeding of prescribed enteral volumes is current standard practice for preterm infants. However, feeding preterm infants in response to their hunger and satiation cues (ad libitum or demand/semi demand) rather than at scheduled intervals might help in the establishment of independent oral feeding, increase nutrient intake and growth rates, and allow earlier hospital discharge. OBJECTIVE To assess the effect of a policy of feeding preterm infants on an ad libitum or demand/semi-demand basis versus feeding prescribed volumes at scheduled intervals on growth rates and the time to hospital discharge. METHODS We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2009), MEDLINE (1966 to Oct 2009), EMBASE (1980 to Oct 2009), CINAHL (1982 to Oct 2009), conference proceedings, and previous reviews. METHODS Randomised or quasi-randomised controlled trials (including cluster randomised trials) that compared a policy of feeding preterm infants on an ad libitum or demand/semi-demand basis versus feeding at scheduled intervals. METHODS We used the standard methods of the Cochrane Neonatal Review Group with separate evaluation of trial quality and data extraction by two review authors. RESULTS We found eight randomised controlled trials that compared ad libitum or demand/semi-demand regimens with scheduled interval regimes in preterm infants in the transition phase from intragastric tube to oral feeding. The trials were generally small and of variable methodological quality. The duration of the intervention and the duration of data collection and follow-up in most of the trials was not likely to have allowed detection of measurable effects on growth. Three trials reported that feeding preterm infants using an ad libitum or demand/semi-demand feeding regimen allowed earlier discharge from hospital (by about two to four days) but other trials did not confirm this finding. CONCLUSIONS Limited evidence exists that feeding preterm infants with ad libitum or demand/semi-demand regimens allows earlier attainment of full oral feeding and earlier hospital discharge. This finding should be interpreted cautiously because of methodological weaknesses in the included trials. A large randomised controlled trial is needed to confirm this finding and to determine if ad libitum of demand/semi-demand feeding of preterm infants affects other clinically important outcomes.