Although the nonmelanoma and melanoma skin cancers encompass the vast majority of skin cancers, there is a large number of other malignancies of the skin that are less commonly confronted by the clinician. Neoplasms of the skin are divided into those that differentiate from the epidermis, dermis, adnexal structures of the skin, and those derived systemically. This review focuses on a discussion of the most frequent malignant neoplasms, and divides them into those that are classically designated nonmelanoma skin cancers (also known as keratinocytic tumors), melanoma, and other less common skin cancers of the skin. New associations are highlighted, as well as new information that can help the clinician to better understand the pathogenesis of many of these entities.