The current review describes the microbiology, diagnosis and management of septic arthritis and osteomyelitis due to anaerobic bacteria in children. Staphylococcus aureus, Haemophilus influenzae type-b, and Group A streptococcus, Streptococcus pneumoniae, Kingela kingae, Neisseria meningiditis and Salmonella spp are the predominant aerobic bacteria that cause arthritis in children. Gonococcal arthritis can occur in sexually active adolescents. The predominant aerobes causing osteomyelitis in children are S. aureus, H. influenzae type-b, Gram-negative enteric bacteria, beta-hemolytic streptococci, S. pneumoniae, K. kingae, Bartonella henselae and Borrelia burgdorferi. Anaerobes have rarely been reported as a cause of these infections in children. The main anaerobes in arthritis include anaerobic Gram negative bacilli including Bacteroides fragilis group, Fusobacterium spp., Clostridium spp. and Peptostreptococcus spp. Most of the cases of anaerobic arthritis, in contrast to anaerobic osteomyelitis, involved a single isolate. Most of the cases of anaerobic arthritis are secondary to hematogenous spread. Many patients with osteomyelitis due to anaerobic bacteria have evidence of anaerobic infection elsewhere in the body, which is the source of the organisms involved in osteomyelitis. Treatment of arthritis and osteomyelitis involving anaerobic bacteria includes symptomatic therapy, immobilization in some cases, adequate drainage of purulent material and antibiotic therapy effective to these organisms.