Bacteroides fragilis, Peptostreptococcus sp., Clostridium sp., and Fusobacterium sp. are the most common clinically significant anaerobic isolates causing anaerobic bacteria in children. The strains of anaerobic organisms recovered depended largely on the portal of entry and the underlying disease. Predisposing conditions to anaerobic bacteremia include: neoplasms, immunodeficiencies, chronic renal insufficiency, decubitus ulcers, perforation of viscus and appendicitis, and neonatal age. Organisms identical to those causing anaerobic bacteremia often can be recovered from other infected sites that may serve as a source of persistent bacteremia. When anaerobes resistant to penicillin are suspected or isolated, antimicrobial drugs such as clindamycin, chloramphenicol, metronidazole, cefoxitin, a carbapenem, or the combination of a penicillin and a beta-lactamase inhibitor should be administered. The early recognition of anaerobic bacteremia and administration of appropriate antimicrobial and surgical therapy play a major role in preventing mortality and morbidity in children.