The study was carried out to investigate the effects of some external egg traits on hatchability using classification tree method (CTM) in Chukar partridge (Alectoris chukar). 1193 eggs were collected from 90 female partridges and 671 chicks were obtained from 847 fertile eggs. Overall hatching, fertility and hatchability of fertile eggs were determined as 56.2%, 79.2%, and 71.0%, respectively. Four variables (egg weight=EW, egg volume=EV, egg length=EL and egg breadth=EB) from external egg traits have a significant effect on hatchability was estimated with 75.6% accuracy by using the CTM. Hatchability (H) was occurred as 80.0% at higher eggs than 18.1 g while H was found as 56.0% at lesser eggs than 18.1 g. When EV and EB were higher than 27.2 and 3.14 cm respectively, H was around 82.1%. But, when EV was higher than 27.2 and EB was lower than 3.14 cm (Node 9) respectively, hatchability was lower than desired. EW greater than 18.1 g hatchability was affected significantly by EV, EL and EB. This situation can be regarded as an indicator for hatching from fertilized eggs. The first report on this subject which the external egg traits of Chukar partridges influenced on hatchability were demonstrated by CTM.