This study was conducted to determine the effect of genotype and fattening system on carcass measurements of lambs and technological properties of the male lamb meat (Musculus longissimus dorsi, MLD). The animal material in the study included 39 Hemsin (H) and 39 Tuj (T) male lambs. Extensive (E), semi-intensive (SI) and intensive (I) fattening systems were applied in the study, which was completed within 90 d. In the E, SI and I fattening groups, a total of 48 lambs, including 16 lambs in each group, were slaughtered. The results of the study indicated that the effect of genotype on the first-hour yellowness (b*), being one of the colour parameters of the MLD, and the effect of the fattening system on 1 h hour redness (a*) and chroma (C*), being among the colour parameters, were statistically significant (P < 0.05). The effect of genotype and fattening system on MLD pH at 45 min (pH(45 )(min)) and 24 h (pH(24h)) after the slaughtering and on the third and seventh hour drip loss (DL %) was statistically nonsignificant (P > 0.05). The effect of genotype and fattening system on DL, cooking loss (CL %) and texture (TT) was nonsignificant (P > 0.05), whereas the effect of these factors on water-holding capacity (WHC %) was significant (P < 0.05). The effect of genotype on external carcass length (ECL), internal carcass length (ICL), internal hindquarter length (IHL), and carcass and leg conformation was statistically significant (P < 0.05). The effect of the fattening system on all the carcass measurements except for carcass conformation, carcass depth (CD) and external chest width (ECW) was statistically significant (P < 0.05). Genotype and fattening system affected the colour and some quality traits of meat and carcass measurements of lambs.