Docosahexaenoic acid (DHA), a fatty acid involved in visual function is provided to the fetus through the placenta and to the newborn infant through human milk. In one study, healthy LBW infants fed formula with 0.3 wt% eicosapentaenoic acid and 0.2% DHA (from MO) for ≈ 11 months had slower growth from 2 months corrected age to 1y. Reduced blood arachidonic acid (AA) or an imbalance between DHA & AA was speculated for impaired growth. This randomized, double-blinded, prospective study in 63 infants tested the hypothesis that MO supplementation (0.2% DHA) in formula-fed LBW infants leads to adequate growth and body composition. Healthy LBW infants (940-2250g at birth) were fed Standard (SF) or MO-supplemented formula (MOF) from full enteral feeding (110-130 kcal/kg/d) to 168 d. For first 8wks, infants were fed premature formula (20 wt% linoleic acid (LA), 2.4% linolenic acid (LNA)) then term formula (20% LA, 2% LNA). Weight (W,g), Length (L,cm), Head Circumference(HC,cm) were measured at entry, 14,28,56,84,112 & 168d, fat mass (FM)& fat-free mass (FFM) at entry, 56, 112, 168d by total body electrical conductance (TOBEC) & plasma & RBC fatty acid levels at 56 & 112d. Statistical analyses were by 2-way repeated measures ANOVA. There were no significant differences for birthweight, W, L, HC, gender, race, gestational age and age at study entry. Plasma and RBC phosphatidylcholine (PC) and phosphatidylethanolamine (PE) DHA levels (wt%) were higher in the MOF-fed group (p<0.001), & RBC PC & PE AA did not differ between groups. In females, no significant differences in growth were found. Male, MOF-fed infants had, by 4 to 6 mo, lower HC, L, W, & FFM than SF-fed infants(p<0.05 to p<0.001). Thus, LBW infants fed formula with 0.2% DHA from MO may have reduced growth which does not appear to be directly related to AA levels in RBC PC or PE. Supported in part by NIH Grant RR-00080, General Clinical Research Center MHMC and Ross Products Division.