Recent advancements in anticancer therapy have produced an array of highly specialized therapeutics that prolong disease-free survival, improve tolerability of treatment, and individualize care. With improved treatments and longer survival, treatment-related toxicities are gaining importance. Dermatologic toxicities are common, with therapy-induced secondary cutaneous malignancies (SCM) of the most frequent and serious for targeted therapies, immunotherapy, and radiotherapy. Often, these eruptive malignant lesions can be treatment limiting and detrimental to quality of life. As such, dermatologists play an important role in multidisciplinary oncologic care teams for surveillance and management of SCM. Proactive dermatologic supervision yields early diagnosis and treatment of SCM, which limits therapy discontinuation thus optimizing treatment through both therapeutic achievement and overall wellbeing.