The effect of selenium (as Na₂SeO₄) and linseed oil on the mass of M. biceps femoris and liver of sheep, as well as on the fatty acid composition and Se, Zn, Fe, Mg and Ca levels of M. biceps femoris, liver and intermuscular fat was investigated. Twenty male lambs of body weight of 25 ± 2 kg were divided into four groups and fed a control diet or experimental diets enriched in 5% linseed oil (LO), 2 ppm Se (SE) or combined addition of 5% LO and 2 ppm Se (LOSE). All experimental diets statistically or numerically decreased the concentration of cis-9C18:1 and saturated fatty acids in muscles and liver, while feeding Se usually significantly or numerically decreased the sum of all assayed fatty acids in muscles and liver. Diets enriched in Se and/or LO (SE and LOSE) significantly increased the Se level in these samples, as well as numerically increased the Zn content in muscles and liver. LO and LOSE significantly or numerically decreased Δ9 desaturation in muscles, liver and fat. LOSE numerically decreased the content of conjugated linoleic acid isomers in all assayed samples.