The study was undertaken to characterize the microbiology of dental abscesses in children and to compare clindamycin and ampicillin/sulbactam in the treatment of facial cellulitis of odontogenic origin. Sixty children with acute facial cellulitis of dental origin underwent surgery (extraction or root canal procedure) within 24 hours of presentation. Pus samples were cultured aerobically and anaerobically. Patients were randomized (1:1) to receive intravenous ampicillin/sulbactam or clindamycin for 48 hours followed by oral amoxicillin/clavulanate or clindamycin for 7 days. A total of 211 bacterial isolates were recovered from 54 samples. The most common aerobic and facultative organisms were viridans streptococci, Neisseria, and Eikenella species. Among anaerobes, Prevotella and Peptostreptococcus species were the most frequent. No treatment failure occurred in either group. Dental abscesses in children are polymicrobial aerobic/anaerobic infections. Treatment of complicated dental infections with ampicillin plus a β-lactamase inhibitor or clindamycin in combination with surgical drainage is very effective.