American pulmonary histoplasmosis is a deep mycosis imported from North America caused by the inhalation of Histoplasma capsulatum. It is endemic in several countries throughout the world and occasional cases have been reported in France, mainly imported from out lying French territories. The most frequent clinical forms observed in immunocompetent subjects are generally benign or silent and usually limited to a fortuitously discovered pulmonary nodule. Massive exposure may lead to an acute primary invasion producing a miliary aspect. Chronic forms simulating tuberculosis are exceptional. Inversely, opportunistic histoplasmosis in AIDS patients can produce an severe multiple organ disease. Ideally, mycelium should be isolated for diagnosis, a task which is easier in disseminated or operated nodular forms. More often, the epidemiological context, clinical and radiological features, the elimination of differential diagnoses and, retrospectively, serology are sufficient for diagnosis. The clinical course is usually favorable. Itraconazole is the treatment of choice for symptomatic or complicated forms.