Dermatophilosis is a skin disease in animals and humans caused by the actinomycete Dermatophilus congolensis. This microorganism causes the skin disease in sheep commonly referred to in Australia as "lumpy wool" or mycotic dermatitis. One proven case of human dermatophilosis and two cases with features which are clinically highly suggestive of the disease from South Australia are described. There has been only one previous report of human infection caused by D. congolensis, which was from the United States in 1961. A brief account of the history, characteristics and life cycle of D. congolensis is given. Human infection in Australia may be not uncommon. A diagnosis can be made by direct microscopy of scab material from the lesions. For this purpose, dry scabs should be sent to the laboratory.