Leibniz’s philosophy has been subject to many studies, but few have addressed aesthetic aspects of his theory. What Leibniz has written concerning aesthetic issues is scattered all through his works, and were we to understand his aesthetic ideas we must bring these dispersed parts together for explanation and interpretation. In the present paper, I attempted to extract Leibniz ideas pertaining to aesthetics, and to introduce, on their basis, a unified aesthetic theory of his, and demonstrate the importance of this theory for his epistemology. First, I brought into light Leibniz’s general ideas concerning aesthetics, and then, due to the epistemological-psychological significance of sense perception in Leibniz’s philosophy, I inquired into it in detail and attempted to clarify the place of sense (and aesthetic) knowledge in human knowledge according to Leibniz. Finally, in the last part, I ventured to divide Leibniz’s approach to sense (and aesthetic) qualities into objective and subjective aspects and investigated each separately.