At the present study, the observations of performance traits including body weight at 8 and 12 weeks of age, age at sexual maturity, egg weight and egg number were analyzed to detect major genes in Yazd native fowl. The probability of segregation for major genes was studied using simple tests including tests of normality, Bartlett, Levene and Fain for residuals and Bayesian analysis. Segregation of major genes was only confirmed for body weight at 8 and 12 weeks of age and egg number. Therefore, based on these results, mixed inheritance model including major gene and polygenic effects is better compared to absolute polygenic model for these traits. Although for body weight at 8 and 12 weeks of age, polygenic effects variance was more than major gene variance, the reverse was true for egg number. Therefore, the main observed variance for this trait is created by major genes effect. Confirmation of major genes segregation for body weight and egg number in Yazd native fowl demonstrates that molecular techniques can be suggested to map the related major genes.