Michael Psellus, Director of the Imperial School of Higher Education in Constantinople, was one of the most famous scholars of 11th century Byzantium. His work is extended in various fields, from Theology and History to Natural Philosophy and Alchemy. This paper examines his work on gold making in comparison with his ideas about the transmutation of Matter, i.e. his work “On gold making” (Περί χρυσοποιίας) and his “Omnifaria Doctrina” (Διδασκαλία παντοδαπή). Psellus in “Omnifaria Doctrina”, a work on Natural Philosophy, presents his philosophical ideas about Nature and Matter. Among others, he tries to explain Nature and its changes using the principles of Nature Philosophy. In this context, he proposes methods and techniques for the transmutation of Matter. The interesting point here is that although Michael Psellus has an ancient Greek philosophical background (mainly Aristotelian), according to which Natural Philosophy is actually distinct from techniques and technology, he nevertheless investigates and proposes techniques for the transmutation of Matter. So, he legitimates the alchemical practice and consequently Alchemy within the epistemological context of the accepted Natural Philosophy of the period.