A supply of omega-3 long-chain polyunsaturated fatty acids (LC-PUFA) is essential for fetal development. Objective: We assessed placental transfer of 13C-labelled fatty acids (FA) 12 hours after oral application. Design: 11 pregnant women received 12h before elective caesarean section 0.5mg/kg 13C-palmitic acid (PA, 16:0), 13C-oleic acid (OA, 18:1n-9), 13C-linoleic acid (LA, 18:2n-6) and 0.1mg/kg 13C-docosahexaenoic acid (DHA, 22:6n-3) orally. Maternal blood samples, venous cord blood and placental tissue were collected and FA concentrations and their tracer content determined. Results: Most 13C-PA and 13C-OA in maternal plasma were in triglycerides (TG), while 13C-LA and 13C-DHA were mainly found in both plasma phospholipids and TG. Placenta/maternal plasma ratios and fetal/maternal plasma ratios for 13C-DHA were higher than for any other FA. Conclusions: We found a significantly higher ratio of 13C-DHA concentrations between cord to maternal plasma than for the other FA, in agreement with preferential transfer of DHA across the placenta.