The need to improve the diagnostic accuracy and sensitivity for skin tumours has led to the development of new non-invasive, in vivo techniques including ultrasound, dermoscopy, digital photography, confocal scanning laser microscopy, magnetic resonance imaging and optical coherence tomography. Of all these in vivo techniques, only confocal scanning laser microscopy allows for the examination of the epidermis and papillary dermis at a resolution approaching histological detail. This review article looks at some of the most important applications of this new technology, highlighting its qualities and limitations.