The Abdâlân-ı Rûm (Abdâls of Rûm) are a loosely-affiliated group of antinomian Sufis who were part of a new movement of renunciation which emerged in the Later Middle Period (ca. 600—900/1200-1500) in the Islamic lands. Gradually submerged into the official Bektâşîye order in the 17th century, the doctrine, literature and practices of this movement became one of the major building blocks in the formation of Bektashism and Alevism. In this paper, I will attempt to analyze the doctrine of the Abdâlân-ı Rûm through the works of its most prominent and prolific representative Kaygusuz Abdâl, who lived in the second half of the 14th and first quarter of the 15th centuries. An analysis of the doctrinal elements of Kaygusuz Abdâl’s works and other works produced by the Abdâlân-ı Rûm, which consist of the hagiographies of prominent masters, poems in cönk and mecmû‘a as well as individual works such as Yemînî’s Fazîletnâme, offers us a two-fold path for evaluation. On the one hand, there are the references to rituals and exoteric doctrinal elements, which allow us to trace the evolution of this dervish group as well as the doctrinal and ritual formation of Alevism and Bektashism. On the other hand is the esoteric material, such as the notion of man as the microcosmos and the Ka‘ba of the spiritual world, the dual aspects of divinity represented by Muhammad and ‘Alî and symbolic exegesis of Qur’anic episodes. While the first path of investigation exposes the facet of evolution and change, the second path traces that of continuity, whereby the defining core of a mode of religiosity is formed. As part of the interpretation of this core, I will trace the role of renunciatory doctrines such as those of the Malâmatî and Qalandarî in the works of Kaygusuz Abdâl, and will thus put his hatred of hypocrisy and constant vigilance over his self into a broader historical context. I will show that it is possible to read the different layers of thinking in the work of Kaygusuz Abdâl in terms of an oscillation between a tendency to blend in, which characterizes the Malâmatî doctrines and accounts for Kaygusuz’s this-worldly moral teachings, and a propensity for radical renunciation, which culminates in a total rejection of society.