Septicaemia concerning Lactobacillus jensenii is exceptional. This bacteria commensal of the normal human flora is known for its low pathogenicity. We report here the observation of a woman, 50 years old, who was admitted in our service for an obstructive acute renal failure and who has presented a septicaemia due to L. jensenii, with a favourable issue by use of antibiotics (amoxicillin-clavulanic acid). This observation permits to report the clinical and bacteriological characteristics of L. jensenii. The importance of the immunodepressed status (diabetes mellitus, chronic renal failure) and use of the endoureteral acts is mentioned.