In this article, we present an easy-to-remember method of evaluating neuropathies. Our proposed method is based on asking four questions about the neuropathy and the patient: "What?," "Where?," "When?," and "What setting?" Answering these questions helps characterize the neuropathy, and this characterization enables the clinician to develop a focused differential diagnosis and plan. After presenting this approach to evaluating neuropathy, we discuss many of the most common chronic axonal neuropathies in the context of this paradigm. Acquired demyelinating neuropathies and inherited neuropathies are discussed in other articles in this issue of SEMINARS IN NEUROLOGY.