Book excerpt: Mohs surgery is a highly effective treatment for certain cutaneous and oral pharyngeal cancers. The procedure allows for the precise and complete removal of cancers while preserving significant amounts of normal tissue. Through the presentation and orientation of the specimens' complete surgical margin on pathology slides, the location of tumor foci and other relevant findings can be correlated with their locations on the surgical wound. The ability to create perfect slides for histological examination lies at the core of effective Mohs surgery. These procedures have a 99 per cent cure rate for certain cancers when implemented correctly. This book describes the methods the dermatologist, pathologist, or technician can use to optimize the Mohs technique and produce the highest-quality slides and highest cure rates possible.