By the time of hatching, the residual yolk sac (RYS) should be completely internalized into the body cavity of the chick through the navel, then the navel should be completely closed (healed). After hatching, the RYS contents are used for general growth including growth of the small intestine. The aim of this study was to verify if there is any effect of navel condition on the growth of small intestinal villi. Jejunum samples from 200 new hatched chicks (at the age of 1 up to 5 days), with the average of 20 chicks per day were obtained, and divided into 2 groups: healed navels and unhealed navels, which were collected and studied histologically. For the first time, this study demonstrated the negative effect of unhealed navel on the growth of small intestinal villi. Morphometric Parameters Measurements of small intestinal also demonstrated villi that the height and the surface areas of villi were increased in healed navel chicks in comparison with unhealed chicks.