Different factors thought to have effect on the mortality of lambs w.r.t. 3 breeds of sheep have been presented. Kacchi breed had the highest lamb mortality (14.2%) followed by Thalli breed (11.9%) while that of Pak-Karakul was the lowest (7.3%). Female lamb had the highest overall mortality rate (10.2%) while that of male was the lowest (8.8%). The lamb had the highest overall mortality rate (36.7%) between age group of 91-120 days (3 months) while between 1-30 days (1 month) of age, mortality was the lowest (4.7%).The lamb had the highest overall mortality rate (12.2%) during spring while it was the lowest (5.5%) in summer. The lamb had the highest overall mortality rate (43.7%) due to pneumonia followed by gastro-enteritis (19.2%) and heat stroke (10.7%). The lamb had the highest overall mortality rate (44.1%) of the dam having 3 years of age followed by 4 years of age of dam (25.7%). Proper feeding of the pregnant ewes, controlled breeding and better management before lambing can play an important role in reducing the mortality.