Black salve is a compound derived from various inert ingredients, but it can be transformed into a corrosive ointment by the addition of bloodroot (Sanguinaria canadensis) or zinc chloride. Black salve products have been advertised as a natural remedy for many ailments, ranging from bee stings to skin cancer. This article reviews the current literature surrounding this compound, which in its corrosive form can be dangerous for use without medical supervision. Patients should be educated about the lack of objective evidence supporting the clinical efficacy of black salve as a skin cancer treatment, as well as the possible cosmetic defects resulting from tissue necrosis secondary to the effects of bloodroot and zinc chloride.