On the basis of eight cases of Bacteroides fragilis septicaemia, the authors review recent data from the literature related to this topic. They first note the increasing prevalence, accounting for approximately 10 per cent of all septicaemias at the present time. They note that the most frequent portals of entry are sites of localised suppuration, related on the one hand to digestive or gynaecological surgery and, secondly, to the post-partum or post-abortum period. From a therapeutic standpoint, they stress the important role of imidazole derivatives (metronidazole or tinidazole) which are the most effective antibiotics at present. Certain authors even suggest their use on a preventive basis in high risk subjects.