Although a comparative study of mysticism in two different schools of thought faces many difficulties, the large number of similarities in theoretical foundations among the schools of mysticism and mystical characters encourages researchers to conduct such studies. Always there is room for a study of Mani and Rumi as the two characters in Persian mysticism. The theoretical foundations of Manichaeism are fundamentally mystical. Asceticism, austerity, vegetarianism, purification of the soul, good deeds, uprightness, cleanness, belief in absolute separation of light and darkness, and of good and evil, as well as the significance of acquisition of knowledge in achieving salvation are central to Manichaeism. According to Manichaeism, knowledge about the divine essence is the basic condition for salvation, and therefore beliefs deriving from the religion are worthy of attention in the field of epistemology. On the other side, Rumi as one of the mystical poets, perhaps the greatest of them, has introduced an order into his mystical attitude whose origins continue to be the subject of scientists’ meditation. Asceticism, purification of the soul, chivalrousness, and separation of light and darkness in Rumi’ s thought as well as the separation of man from his origins, indifference towards the material world, and especially the significance of knowledge of God and self-knowledge are very important components of the structure of the epistemologies of Mani and Rumi. Having explored the epistemological elements of the mysticisms of Mani and Rumi, the present article tries to find links that might exist between the two views.