Muskoxen (Ovibos moschatus) are large ruminants living in Arctic habitats, and their diet is usually dominated by grasses, sedges and dicots. Muskoxen have an exceptional ability to fatten during spring and summer to support their energy needs during the arctic winter. However, little is known about the fatty acid (FA) composition of muskox meat, adipose tissue and liver. The objective of this study is to characterize the FA composition in samples from muskox females and males from Western Greenland. Muskox samples (muscle, adipose tissue and liver) from adult female (n = 12) and male (n = 8) were collected around Kangerlussuaq (West Greenland) during the winter hunting season of 2014. Samples were freeze-dried and lipids were extracted using dichloromethane and methanol (2:1, v/v). Total lipids were measured gravimetrically. Fatty acid methyl esters (FAME) were prepared from the lipid extracts with sodium methoxide in methanol followed by hydrochloric acid in methanol. FAME were quantified by GC-FID using a Shimadzu GC-2010 Plus (Shimadzu, Kyoto, Japan) equipped with a TR-CN100 capillary column (100 m, 0.25 mm i.d., 0.20 µm film thickness, Teknokroma, Spain). FAME were expressed as g/100 g of total peaks and data were analyzed using the PROC MIXED of SAS (SAS Institute Inc., Cary, NC) with a model that included the sex (female vs. male) as the single effect. Muskox muscle, adipose tissue and liver contained about 396, 916 and 150 mg/g DM of total lipids, respectively. Females showed the highest fat content (P = 0.046) compared with males, which might be an additional energy reserve for the late-winter lactation. More than 60 FA were detected in muskoxen samples, however, the 18:1cis-9 was the dominant FA in muscle and adipose tissue, presenting more than 43% and 32% of total FA, respectively. The great oleic acid concentration in muskoxen fats might indicate a higher lipogenic activity in these animals. Differences between sexes on the FA composition were minor in liver and more pronounced in adipose tissues. In general, males presented more levels of branched-chain FA, while female presented more oleic acid.