This paper summarizes the literature concerning the effects of administering (1) long-chain polyunsaturated fatty acids (LCPUFA), (2) probiotics and/or (3) prebiotics to preterm infants. Clinically relevant, short- and long-term efficacy outcomes, such as those related to a reduced risk of disease, as well as outcomes related to safety, were sought. MEDLINE and the Cochrane Library literature searches performed in September 2010 were limited to randomized controlled trials, their systematic reviews or meta-analyses. LCPUFA supplementation, particularly docosahexaenoic acid (DHA), of infant formula for preterm infants has consistently demonstrated better visual development of preterm infants compared with unsupplemented formulas. There is increasing evidence to suggest that LCPUFA supplementation for preterm infants is also related to improvements in more global measures of development, without any adverse effects. It is, however, important to note that the DHA doses tested in the infant formula interventions for preterm infants have been rather conservative. Newer studies comparing dietary DHA concentrations that match in utero accumulation rates with dietary DHA concentrations typical in the milk of women consuming little fish or in supplemented infant formulas demonstrate that these higher DHA doses are related to improvements in domains of cognitive development. Although further work is needed to better understand the optimal DHA requirements of preterm infants, it is clear that a dietary source of DHA is important to support neurodevelopment. To date, the most promising application of probiotics in preterm infants is the prevention of necrotizing enterocolitis by the administration of certain probiotics. Many other benefits of administering probiotics and/or prebiotics to preterm infants are, however, largely unproven. Efficacy and safety should be established for each probiotic and/or prebiotic product. Further research should specify strain-specific outcomes and determine optimal dosing schedules. Safety and long-term follow-up studies are of particular interest.