Most current diagnostic criteria for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) do not make use of sensory nerve conduction studies (NCSs). To investigate if surface sensory NCSs are clinically relevant in differentiating CIDP from axonal polyneuropathy, we conducted a retrospective cohort study of patients referred for electrodiagnostic testing to evaluate for CIDP. We found that sensory conduction velocity (CV) slowing is a highly specific, albeit insensitive, marker for differentiating CIDP from axonal polyneuropathy.