Freedom is a fundamental concept in Kant's philosophy, including theoretical and practical philosophy, though its role in the latter is more significant. In his philosophy of ethics Kant considers freedom as the basis of his reasoning for ethics and in order to rule out the view that considers ethics as illusion he maintains that if we possess a free will, then ethics will turn out to be real and ethical laws will be valid for all.This article is an attempt to study the role of freedom in Kant's philosophy of ethics with special reference to his two main books on practical reason, namely, The Foundations of the Metaphysics of Ethics and Critique of Practical Reason.