Background: Plant-based intravenous lipid emulsions have been shown to contribute to parenteral nutrition-associated liver disease (PNALD). There is mounting evidence that fish oil-based emulsions may prevent this liver injury. This study compares 5 emulsions with different fat compositions and their effect on hepatic steatosis, one of the first hits in PNALD. Methods: C57BL/6J mice were placed on a fat-free diet and randomized into 5 equal groups. Each group received one of the commercially available intravenous lipid emulsions (Intralipid [Baxter/Fresenius Kabi, Deerfield, Ill], Liposyn II [Hospira Inc, Lake Forest, Ill], ClinOleic [Baxter/Clintec Parenteral SA, Cedex, France], SMOFlipid [Fresenius Kabi, Bad Homburg, Germany], or Omegaven [Fresenius Kabi Deutschland GmbH]) or normal saline. Liver enzymes, degree of steatosis, and fatty acid compositions were analyzed after 19 days. Results: Intralipid, Liposyn II, ClinOleic, and SMOFlipid groups all demonstrated moderate steatosis with hepatic fat contents of 17.4%, 21.9%, 22.5%, and 12.6%, respectively. Omegaven mice, however, had normal livers. Saline control mice developed biochemical evidence of essential fatty acid deficiency (EFAD). Lipid supplementation with Intralipid, Liposyn II, and Omegaven prevented the onset of biochemical EFAD, whereas administration of ClinOleic and SMOFlipid did not. Conclusion: The fish oil-based lipid emulsion Omegaven prevented hepatic steatosis and EFAD in this murine model. ω-3 fatty acids may be efficacious in preventing PNALD and should be explored in the development of novel lipid emulsions.