Seven cases of squamous cell carcinoma (SCC) arising in chronic neuropathic plantar ulcers of leprosy are described. These patients (average age 59 years) presented over a 5-year period. The mean duration of neuropathic ulceration until diagnosis of SCC was 24.5 years. Six patients required limb amputations and 3 underwent lymphadenectomy for involved nodes. One patient died of disseminated disease. The history of the eponym "Marjolin's ulcer' is traced and a case put forward for recognition of malignant change in neuropathic ulcers as yet another example of Marjolin's ulcer. A plea is made for an increased awareness of the possibility of malignant transformation in chronic neuropathic ulcers in order to effect an early diagnosis of a potentially aggressive cancer. This is the first report of its kind in South Africa. Similar cases, however, have been reported from other parts of the world where leprosy is endemic.