This work was done to investigate the immune fitness of newly hatched chicks in four local improved Egyptian strains using immunoglobulin-Y (IgY) Index transferred from hens through egg yolk to offspring. The strains used were Mandarah, Matrouh, Silver Montazah and Inshas. 36 hens and 9 cocks of 18 weeks old from each strain were used. IgY concentration was determined in serum of hens and newly hatched chicks. Also, the egg yolk was separated to determine IgY levels in egg yolk. The results of Mandarah strain showed the highest concentration (P≤0.05) of IgY that transferred to egg yolk and offspring, followed by Matrouh, Silver Montazah and Inshas strains that had the lowest (P≤0.05) concentration of IgY. There was significant positive correlation between the levels of total serum IgY and total yolk IgY level in the four breeds. However, Mandarah strain had the highest positive correlation indicating that Mandarah chicks should have the highest passive immunity against infectious diseases during early life. This may contribute to breeding programs when fitness of the offspring is a concern, as this may affect general health status of birds having high immunity that reduces the use of antibiotics and hence favoring organic production of chicken.