One hundred patients (71 males and 29 females) with bacterial meningitis were randomly assigned into two therapeutic regimens. Patients in group I were intravenously given ceftriaxone (CRO: Rocephin) to adults and intramuscularly to children once daily in a dose of 100 mg/kg/day. Patients in group II received ampicillin 160 mg/kg/day and chloramphenicol (AMCL) 100 mg/kg/day (i.v. to adults and i.m. to children) every 6 h. No significant difference was observed between the two therapeutic regimens with regard to mortality, time taken to become afebrile, fully alert and sequelae. Seven patients in the CRO group died compared to 10 in the AMCL group. The mean number of days taken to become afebrile were 3.4 and 3.5, and to become fully alert 3.9 and 3.5 for groups I and II, respectively. CRO administered in a single daily dose appears to be as effective as a combination of ampicillin and chloramphenicol given every 6 h in the treatment of acute bacterial meningitis. However, the once daily dose is more appropriate for use especially in areas where nursing care is limited.