The importance of long-chain polyunsaturated fatty acids (LCPs) in the development of preterm infants is now well accepted but the source of dietary LCPs to be added to infant formulas remains controversial. We measured dietary intakes, fecal output, and percentages of intestinal absorption of n-6 and n-3 LCPs in healthy preterm infants fed exclusively preterm breast milk (PBM; n = 20), formula without LCPs added (NLCPs; n = 19), formula with LCPs derived from phospholipids (PL-LCPs; n = 19), or formula with LCPs from triacylglycerols (TG-LCPs; n = 19). Intestinal absorption of arachidonic acid was not different in the four groups but docosahexaenoic acid was better absorbed from PL-LCPs than from PBM (88.3 +/- 1.8% compared with 78.4 +/- 4.0%, P < 0.05) Total absorption of n-6 LCPs was not different between groups but total n-3 LCPs were better absorbed from PL-LCPs than from PBM or TG-LCPs (88.7 +/- 1.9%, 79.2 +/- 4.4%, and 80.4 +/- 2.2%, respectively). In conclusion, docosahexaenoic acid and arachidonic acid were absorbed as efficiently from TG-LCPs formula as from breast milk fat. Absorption of docosahexaenoic acid and n-3 LCPs was greater from PL-LCPs formula than from PBM or TG-LCPs formula.