Recently, in a supplementation study over six months, it has been demonstrated that re-esterified omega-3 fatty acid triacylglycerols (n3-FA-rTAGs) led to a higher increase in omega-3-index compared to identical doses of n3-FA ethyl-esters (n3-FA-EEs), suggesting a better long-term bioavailability. The aim of this study was to examine whether differences occur between the two forms in affecting fasting serum lipid levels. 150 dyslipidemic statin-treated participants were randomized to corn oil as a placebo or fish oil either as rTAG or EE in identical doses (1.01g EPA+0.67g DHA). No changes in total cholesterol, HDL or LDL levels were observed. In the rTAG-group, but not in the EE-group, fasting serum TAG levels were significantly reduced from baseline after three and six months. There was no significant difference between the two n3-FA-groups. However, serum TAG levels were significantly lowered after six months in the rTAG-group compared to the placebo-group in contrast to the EE-group. Copyright © 2011 Elsevier Ltd. All rights reserved.