Fifty-two children were included in this study to evaluate and compare short- versus standard-length ceftriaxone therapy for bacterial meningitis. The duration of the short-course regimens was 4, 6 and 7 days for Neisseria meningitidis, Hemophilus influenzae and Streptococcus pneumoniae, respectively. The standard-length regimens were twice as long. On the basis of a computer-generated randomization list, 26 children were assigned either to the short- or to the standard-treatment regimen. Ceftriaxone was given intravenously once daily in a dose of 60 mg/kg after an initial loading dose of 100 mg/kg. The population characteristics, the severity of disease and the cerebrospinal fluid (CSF) findings were similar in the two study groups at admission. Bacteriological and clinical response were comparable. There were no significant differences in the incidence of neurological complications, prolonged fever (greater than or equal to 10 days), persistent pleocytosis and side effects between the two groups. Hearing loss occurred in 3 patients in the standard-length group and in no patients in the short-course group. Diarrhea was the only side effect and occurred in 14% of the patients. The results of the study indicate that the short-duration regimen was adequate for the treatment of meningitis caused by the three major meningeal pathogens. However, the small number of patients do not justify the adoption of the short-course regimen for all children with meningitis. At present, prolongation of ceftriaxone therapy or discontinuation of the drug under strict clinical observation of the patient should be considered in some cases.