Coccidioidomycosis is a systemic disease caused by the dimorphic fungus Coccidioides, endemic in parts of the Southwestern USA and Central and South America. Two species, Coccidioides immitis and Coccidioides posadasii, were differentiated. Primary cutaneous coccidioidomycosis (PCC) has been reported rarely. An unusual case of PCC characterized by a persistent solitary lesion diagnosed in Italy in an immunocompetent Italian nun living in Argentina is described. The isolate was identified by sequence analysis as C. posadasii. Antibody screening was negative. A total of 39 cases of PCC have been reported in the literature. Infections occurred as a consequence of traumatic implantation in a natural setting in endemic areas or of accidental inoculation in laboratory workers. Importance of accurate investigation of travel history and of occupational hazards to laboratory workers is outlined.