Cefdinir (CFDN, FK482) was evaluated in children with infections. CFDN was given at a daily dose of 6.4-19.8 mg/kg in 2 or 3 divided portions. CFDN was effective in 94% of 32 cases with respiratory tract, middle ear, urinary tract or skin structure infections. Side effects were loose stool and diarrhea (12.5%). In a pharmacokinetic study, 6.0 mg/kg of CFDN was given to each of the subjects before meal. Cmax was 0.81 +/- 0.38 microgram/ml, T 1/2 was 2.31 +/- 0.77 hours. Antibacterial activity against Staphylococcus aureus was the most excellent of oral cephem antibiotics tested. The data suggest that CFDN 10% granular preparation is safe and effective when used in children with infections caused by susceptible bacteria.