Autoscopic phenomena involve the illusory reduplication of one's own body. The literature on the topic is widely scattered and suffers from considerable terminological and conceptual inconsistencies. This article proposes a classification scheme based on phenomenological criteria. Along with examples of illustrative cases, we outline the main features of autoscopic hallucinations, heautoscopy proper, the feeling of a presence, the out-of-body experience, and negative and inner forms of autoscopic phenomena. We also discuss the need for a differentiation of autoscopic phenomena from reduplicative paramnesias and the misidentification syndromes. Finally, the concept of a neuromatrix (Melzack, 1990) is proposed as a starting point for the understanding of the neuronal mechanisms underlying autoscopic phenomena.