The effect of supplementary dried brewer’s yeast, Saccharomyces cerevisiae, during 100 days rearing period on meat quality of lambs was investigated. Twenty four male Kamieniecka breed lambs were divided into two groups: I - control, II - experimental - supplemented with preparate Inter Yeast^® S, containing Saccharomyces cerevisiae. Meat quality was determined on samples of M. longissimus lumborum (LL) and M. quadriceps femoris (QF), based on the following parameters: chemical composition, physicochemical properties, the fatty acid composition and profile of intramuscular fat, and sensory properties. Meat of lambs from group II contained more dry matter (0.78%) and intramuscular fat (0.33%), compared with control lambs (P<0.01). An increase the red colour component a* (P<0.01) and improvement the water-holding capacity (P<0.01) of meat were also found in the experimental group. The concentrations of C_14:1, C_18:2 and C_22:6 fatty acids (P<0.05) and conjugated linoleic acid C_18:2 cis9trans11 were higher (P<0.01) and the content of C_20:4 was lower (P<0.01) in the intramuscular fat of lambs from group II. The above changes had no influence on the sensory properties of meat. The content of dry matter and protein was higher, and cooking loss was lower (P<0.001) in LL than in QF muscle. The sensory properties were better in QF muscle.