Rickettsia conorii infection is endemic in the Mediterranean basin, where it is known as Mediterranean spotted fever, also known as Boutonneuse fever and Marseilles fever. We report the case of a 66-year-old diabetic man who presented a severe form of the disease, complicated by acute renal failure, thrombocytopenia and encephalitis. Diagnosis was confirmed by indirect immunofluorescence assay. Despite appropriate treatment, severe neurological sequelae have remained. Medical literature on encephalitis caused by R. conorii is also reviewed.