Ceftriaxone treatment (50 to 80 mg/kg once daily) was given to 201 children between 1 month and 18 years of age. There were 201 serious bacterial infections, including epiglottitis, pneumonia, cellulitis, osteomyelitis, septic arthritis, pyelonephritis, sepsis, and meningitis. The common pathogens responsible for pediatric infections isolated from these patients included Haemophilus influenzae, Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, and Escherichia coli. The overall clinic cure rate was 94%. Ten patients were clinically improved but not cured. There were two clinical failures. Bacteriologic failure occurred in six patients. The overall bacteriologic cure rate was 97%. Twenty patients (10%) experienced adverse effects; none required discontinuation of therapy. The efficacy, safety, spectrum, and convenience of ceftriaxone monotherapy make this antimicrobial agent a candidate for the treatment of choice of selected serious pediatric infections.