We reported the first case of Rothmann-Makai syndrome associated with mononeuropathy in a 31-year-old woman. In June 1989, she noticed several small subcutaneous nodules in the bilateral upper arms. On July 2, she woke up because of severe pain below the knee in the right leg which lasted 15 hours. On admission, subcutaneous nodules were recognized on bilateral upper arms, abdomen, gluteal regions and thighs. None of these nodules were associated with local heat or pain. Muscle weakness and dysesthesia were observed in the right foot, but deep tendon reflexes were normal. Electrophysiological studies revealed a decrease of the amplitude of action potential and of the conduction velocity in the right tibial nerve. Microscopic examination of skin biopsy showed lipolysis and diffuse lymphocyte infiltration (panniculitis) and perivascular lymphocyte infiltration was also observed. Routine laboratory data including peripheral blood, ESR, blood chemistry, and CRP were in the normal range and antinuclear antibodies and LE cells were not detected. By those findings, she was diagnosed as Rothmann-Makai syndrome associated with mononeuropathy. Steroid treatment was effective on both skin lesions and mononeuropathy. Steroid treatment was effective on both skin lesions and mononeuropathy. We concluded that this mononeuropathy may be induced by a ischemic change which may be caused by panniculitis.