Boutonneuse fever (BF) is usually considered to be a benign rickettsiosis. However, severe presentations, resembling Rocky Mountain spotted fever, have been reported. There are few neurological complications, except in serious forms of the disease. We present a case of meningoencephalitis in a male adult suffering from BF, and we review the clinical, etiopathogenic and diagnostic aspects among the cases previously reported. We conclude that BF encephalitis would have the following characteristics: a) they mostly affect elderly males; b) they cause altered consciousness level, headaches and low rate of meningeal signs; c) absence of "tâche noir"; d) cerebrospinal fluid with slight pleocytosis and/or increased level of proteins, and normal glucose values; e) computerized tomography without significative changes, and f) high rate of morbidity and mortality. We emphasize that we should consider BF in the differential diagnosis of our environmental encephalitis.