It is well known that in India, over the last two thousand five hundred years or more, there has been a pervasive belief in the doctrine of Karma. Various forms and variants in which this doctrine has found expression in the multifarious texts and metaphysical systems have drawn a good deal of attention. The present paper, however, is an attempt at analysing the function of this doctrine, in the sustenance of the traditional social system, and particularly the scheme of social stratification. As we shall see, an unshakable faith in this doctrine by people belonging to all strata of society provided tremendous strength to the caste hierarchy based on birth, and ensured a secure place for the Brāhmanas and their progeny on the top of the social pyramid.