In vivo cutaneous surface microscopy, epiluminescence microscopy, dermatoscopy and dermoscopy are terms that all describe the same process of examination of cutaneous lesions with an incident light magnification system with oil at the skin-microscope interface. Increased investigation in surface microscopy has occurred in the last decade, primarily because of the introduction of inexpensive hand-held instruments. Research has focused particularly on morphological definitions, diagnostic models and image analysis systems. In this paper, these issues are discussed, and the relevant controversies highlighted.