Abstract: In this study, the growth traits of Karakas and (Ile de France x Akkaraman (G1)) x Karakas crosses (F1) (IDFAK) lambs were investigated. Ewes in the flock were not milked and lambs were subjected to unlimited suckling regime without weaning. Least squares means of weights of IDFAK and Karakas lambs at birth and 1-6th months were 4.67 and 4.08 kg (p<0.01), 9.16 and 9.49 kg, 14.87 and 15.44 kg, 22.31 and 24.12 kg, 30.84 and 32.51 kg, 35.34 and 33.79 kg, 39.51 and 35.99 kg, respectively. Least squares means of daily live weight gains of IDFAK and Karakas lambs from birth to 1., 2., 3., 4., 5. and 6th months of age and between 3-6th months were 0.159 and 0.170 kg, 0.174 and 0.184 kg, 0.198 and 0.219 kg, 0.221 and 0.235 kg, 0.207 and 0.197 kg, 0.196 and 0.177 kg, 0.202 and 0.172 kg, respectively. The survival rates of IDFAK and Karakas lambs until 60th day were 95.94% and 89.79%, respectively (p<0.05). It seems that (Ile de France x Akkaraman (G1)) x Karakas crosses (F1) lambs reached to marketing age more short time than Karakas lambs. It could be concluded that Ile de France x Akkaraman (G1) genotype is useful in improving lamb production in Karakas sheep and desired growth could be obtained especially for cross lambs during 5th and 6th month age.