This chapter covers epidermal premalignant and malignant conditions which include color images of seborrheic keratosis, actinic keratosis, Bowen’s Disease, erythroplasia, basal cell carcinoma, squamous cell carcinoma (SCC), verrucous carcinoma and keratoacanthoma. At the end of this chapter differential diagnosis of all these are also mentioned. The presence of buds at the base in proliferative actinic keratosis should not be confused with SCC. Bowen’s disease can be distinguished from podophyllin treated condylomata acuminata by the presence of metaphase figures. Lymphovascular invasion in SCC is associated with poor prognosis. Erythrophagocytosis of tumor cells may be seen in SCC. Marked intercellular edema in verrucous carcinoma gives the cytoplasm a glassy appearance. Mitosis in keratoacanthoma is generally limited to the basal layer.