We report a patient with scleromyxoedema and peripheral neuropathy treated successfully with thalidomide. An objective evaluation was carried out using histopathology, cutaneous ultrasonography and magnetic resonance imaging (MRI). A 67-year-old woman presented with a leonine face, generalized thickened skin, an underlying peripheral neuropathy and a monoclonal gammopathy. She was treated with thalidomide 100 mg/day. After 20 months of therapy, there was a dramatic clinical improvement in the skin lesions, and the neuropathy also improved. Cutaneous ultrasonography showed a reduction in dermal thickness, whereas the results of the cutaneous MRI were inconclusive. Thalidomide appears to be effective in scleromyxoedema. Its specific effect on the underlying monoclonal gammopathy might have contributed to the improvement in the skin and neurological symptoms. In this case, assessment of cutaneous improvement with cutaneous ultrasonography was superior to that of cutaneous MRI. Thalidomide should be considered for the treatment of scleromyxoedema despite the presence of an underlying peripheral neuropathy.