Eight Saidi lambs were randomly divided into two equal groups. The initial average live body weight values were 22.42 and 23.15 kg for groups 1 and 2, respectively. The first group did not receive fenugreek seeds and served as a control group, while the second group was supplemented with 3% fenugreek seeds and served as a treated group. Both treatment groups were fed roughage and concentrate diets ad libitum during this study. The experimental period lasted for 20 weeks (140 days) followed by ten days digestibility trial. At the end of the experimental period, all animals were slaughtered. The obtained results showed that supplementation of dietary fenugreek seeds induced significant increase of total feed intake (P<0.01), feed conversion (P<0.01), daily gain and live body weight. No significant differences were found between control and fenugreek groups in digestibility of DM, OM, CP and CF. On the other hand, fenugreek treated lambs showed slightly higher EE and NFE digestibility compared to control group. Supplementation of dietary fenugreek seeds had insignificant elevation of plasma total protein and plasma glucose concentrations while total cholesterol concentration had a significant (P<0.01) reduction as compared with control. Supplementation of dietary fenugreek seeds increased hot carcass and dressing percentage. The proportion of muscle/ bone and muscle/fat ratios increased in lambs treated with fenugreek seeds. Most offal parts and Left carcass side weight and carcass cuts were heavier in fenugreek - treated lambs than control. Fenugreek- treated lambs had heavier shoulder, loin, leg Semimemberanosus, Supraspinatus and Longissimus dorsi muscles when compared with the control. Chemical analysis of samples of Semimemberanosus, Supraspinatus and Longissimus dorsi muscles showed significant reduction of fat percentage and a slight increase of protein for lambs fed fenugreek diet than control.