This study was designed to examine the effect of birth weight, gender, birth type, lambing season, and dam parity and health status on lamb morbidity and mortality during the neonatal (first four weeks of life) and post-neonatal (first 5-12 weeks of life) periods in lambs born in two flocks in the 2009 lambing season in Kars, Turkey. EPI INFO 6 was used to determine differences in morbidity or mortality rates and risk according to risk factors including birth weights, genders, type of birth, lambing seasons, and parity and health of dams. The significance level was set at P<0.05 for all comparisons. The neonatal morbidity and mortality rates (48% and 33.3%, respectively) and risk of the lambs in the low birth weight group were significantly higher than those of the lambs in the medium birth weight (18.9%, chi(2)=10.4, OR=3.9 for morbidity and 1.6%, chi(2)=32.5, OR=30, for mortality) and high birth weight (9.8%, chi(2)=26.9, OR=8.5 for morbidity and 1.2%, chi(2)=46.5, OR=42.7 for mortality) groups (P<0.01 and P<0.001, respectively). The neonatal mortality rate and risk of lambs born in the winter season (9.2%) were significantly (P<0.01) higher than those of lambs born in the spring season (1.8%, chi(2)=9.6 and OR=5.5). Lambs born to primiparous ewes had a neonatal morbidity rate (29.6%) and risk significantly higher than those of ewes at second parity (13.9%, chi(2)=6.4, OR=2.6) and third parity (11.1%, chi(2)=7.8, OR=3.3) (P<0.05 and P<0.01, respectively). Similarly, lambs born to primiparous ewes had a neonatal mortality rate (14.8%) and risk significantly higher than those of ewes at second parity (2.9%, chi(2)=9.3, O=5.7), third parity (0%, chi(2)=14.1) and >= 4 parity (2.4%, chi(2)=4.2, OR=6.9) (P< 0.001, P<0.001 and P<0.05, respectively). Lambs born to ill ewes had a neonatal morbidity rate (64.7%) and risk significantly higher (P<0.001) than those of lambs born to healthy ewes (13.8%, chi(2)=30.38, OR=11.4). In the present study, it was concluded that the most significant risk factors for lamb morbidity and mortality were season of birth, parity, birth weight and health status of dams. Therefore, timely implemented health and management measures targeting these factors are required to reduce disease and death.