A healthy 26-year-old man, without initially presenting fever, rapidly developed a focal right pontomedullary deficit associated with an aseptic lymphocytic meningitis. The diagnosis of Listeria infection was confirmed by blood cultures. CT and MRI demonstrated an abscess extending from the superior cerebellar peduncle to the lateral portion of the medulla. Immunological controls gave no indication of deficiency. With ampicillin therapy, started on the 5th day, clinical recovery was almost complete, but a soft palate right paresis persisted as the unique sequel. Antibiotic therapy was maintained for 5 months up to normal CSF and CT. One year after the onset, MRI was also normal. The rare nature of listerial abscess in the brainstem is discussed with regard to rhombencephalitides.