The authors studied, with a time-kill curve method, in a derived Hafiz medium broth the bactericidal effect of 7 antibiotics and 4 associations against N. meningitidis. Their results show a better bactericidal effect for penicillin G, ampicillin and chloramphenicol. Pefloxacin and ceftriaxon are less efficient. The association ampicillin + chloramphenicol in vitro shows no antagonism and has a good bactericidal activity at the early stages of bactericidal killing with N. meningitidis.