Treatment of cancer has shifted dramatically over the past 2 decades. Targeted agents are used to block pathways known to drive tumor growth. Immunotherapy agents work by reversing cancer's ability to evade immune checkpoints, resulting in effective immune responses. With these approaches come new adverse effects that may be acute or delayed and require early identification. Notably, these toxicities can mimic other common conditions. Thus, it is important for primary care providers to be knowledgeable to detect issues and respond appropriately.