Abstract The objective of the experiment was to accumulate n-3 fatty acids and conjugated linoleic acids (CLA) in muscle and subcutaneous fat in Skudde lambs by feeding grass to concentrate. In total, 14 male lambs were allotted into two feeding groups at 18 kg live weight. Lambs were kept either on pasture (pasture, n = 6) or in stable (concentrate, n = 8). The daily gain of concentrate fed Skudde lambs (113 g/d) was lower compared to pasture kept animals (127 g/d). The carcass composition and meat quality was only slightly affected by the two feeding systems. Meat colour was significantly ( P < 0.05) darker in lambs fed on concentrate. The linolenic acid (C18:3 n-3) of grass was absorbed and deposited in the intramuscular ( P < 0.05) and tail fat. Pasture feeding increased the concentration of CLA cis-9, trans-11 ( P < 0.05; 11.3 versus 21.3 mg/100 g) and C18:1 trans-11 (TVA; P < 0.05; 21.7 versus 45.6 mg/g) in muscle fat of Skudde lambs. The ratio of n-6/ n-3 fatty acids was significantly lower in grass fed lamb muscle and adipose tissue fat ( P < 0.05) but even in concentrate fed lambs the ratio was beneficial low.