Enteral and parenteral glutamine supplementation in preterm infants has been shown to have some beneficial effects on neonatal morbidity and mortality, although the results are controversial. In this study, we aimed to determine if long-term glutamine-supplemented enteral nutrition affects growth parameters in very-low-birth-weight (VLBW) preterm infants. Preterm infants with a birth weight of < or = 1500 g were assigned to receive enteral glutamine supplementation (300 mg/kg/day) or placebo between 8-120 days (4 months) of life. At the end of each month, growth parameters [weight, length, head circumference, left upper mid-arm circumference (MAC) and left mid-thigh circumference (MTC)] were determined and enteral glutamine dose was adjusted according to the current weight. In VLBW infants (n = 69), the glutamine-supplemented group (n = 36) had significantly higher mean weight, length, head circumference, MAC and MTC than the control group (n=33) at the end of the fourth month. These findings suggest that long-term enteral glutamine supplementation may lead to significant improvements in growth in all body measures in VLBW infants, possibly in a time-dependent pattern.