SummarySporadic cases of Legionnaires’disease, a recently described pulmonary infection, have been reported from several countries. The ease of a 67-year old Belgian who developed a similar pulmonary infection, is described.The clinical picture included fever, cough, dyspnoea and confusion.The chest roentgenogram showed multilobar pulmonary involvement with tendency to nodular consolidation.The patient was treated with ampicilline and cephapirine and recovered slowly.The antibody titer against Legionella pneumophila, determined retrospectively by means of an indirect fluorescent-antibody test was 1: 1024.