Piperacillin is a potent antibiotic and tazobactam is an inhibitor of β-lactamase. Piperacillin-tazobactam combination has a broad spectrum of activity encompassing most gram-positive, gram-negative, aerobic and anaerobic bacteria, including many producing β-lactamase organisms. The dose of piperacillin is 90 mg/kg every 6-8 hours in infants aged 1 month to 1 year. In children, the recommended doses of piperacillin and tazobactam are 50 mg/kg and 6.25 mg/kg or 100 mg/kg and 12.5 mg/kg, respectively, every 6 hours. Piperacillin and tazobactam are mainly excreted as unchanged drugs in the urine, and high biliary concentrations are achieved. The piperacillin elimination half-life is variable in neonates and ranges from 3.5 to 14 hours, whereas in infants aged between 1 and 6 months, the half-life is 47 min. The piperacillin-tazobactam combination is effective, safety, and well tolerated in infants and children. After a single intravenous infusion of 50 mg/kg piperacillin to infants and children aged 1 month to 12 years, the mean plasma concentrations of piperacillin rapidly decayed and were