SummaryTen squamous cell carcinomata, mainly on the palmar surface of the hands, have occurred in patients who had had atabrine dermatitis during the Second World War. The lesions occurred only in those individuals who had developed a severe lichen planus‐like reaction to the drug, leading to anidrosis. Many years after the War these patients developed two active sequelae, namely, peculiar scaly red plaques and fungating warty growths. Practically all of these lesions, which were situated mainly on the hands, have become malignant after a time interval of many years. It is suggested that there is sufficient evidence to indicate that atabrine under certain circumstances, namely, in patients with tropical anidrotic asthenia, almost certainly induces skin cancer. It is thought that this is the first report in medical literature of the occurrence of these change