The authors report a case of multiple and spleen pyogenic abscesses caused by Peptostreptococcus spp., in a patient who recently underwent laparotomy due to duodenal perforation. He was successfully treated by means of intensive and extended antibiotherapy. We would like to stress the importance of an early and etiological diagnosis performed by percutaneous puncture and bacteriological study, in order to start a selective antibiotherapy. Other therapeutical possibilities are discussed.