An open retrospect study, including five patients, has been entered on, in order to estimate the efficacity and the tolerance in a more than sixty years old person, of the association ampicillin-cotrimoxazole for the treatment of the meningitis due to Listeria monocytogenes. In the infectious sphere, all the patients recovered; one death, by pulmonary embolism at the 21sh day of evolution, is to be deplored; two erythematous rashes have been observed. These preliminary results are encouraging and incite to carry on the evaluation of this protocol, which could replace the classical therapy; ampicillin-aminoglycosides, where only the ampicillin reaches effective concentrations on the level in the cerebro-spinal fluid.