Ultrasonographic nerve enlargement has primarily been reported in patients with inflammatory neuropathies such as chronic inflammatory demyelinating polyneuropathy (CIDP), multifocal motor neuropathy, Guillain-Barre syndrome, vasculitic neuropathy and leprosy. Nerve ultrasonography is a promising diagnostic supportive tool for inflammatory neuropathies. The ultrasonographic findings that are currently useful are 1) nerve enlargement primarily suggests the existence of inflammatory or demyelinating neuropathies and 2) for patients with CIDP or demyelinating Charcot-Marie-Tooth disease, the pattern of nerve enlargement is noted, and this pattern is useful for discriminating between these diseases. More precise evidence of ultrasonographic findings for inflammatory neuropathies should be established in the future.