The basic components of human body are Dosha, Dhatu and Mala. The healthy state of body rests on the state of dynamic equilibrium of these components. Human body is in a continuous exposure to external and internal stressors which make the body vulnerable to disease. But the tendency to have disease is prevented by many factors within the body. Oja is one of the factors that prevent the body from illness. Ojas is nothing but the pure essence of all Dhatu of the body. Abnormalities of Ojas result in many illness and loss of strength and stamina. So it is utmost essential to manage Oja in optimal quantity and quality so that the body will enjoy healthy life. The present study is carried out with an aim to have proper understanding of the Ojas with special reference to immunity and access its clinical importance.