An acute osteoarticular infection in a child is most often hematogenous. The infection manifests as osteomyelitis or septic arthritis. The most common causative organism is Staphylococcus aureus. Medical advice is usually sought within 2 to 6 days from the onset of symptoms. A child with an osteomyelitis in a lower extremity characteristically presents with limping with or without notable local tenderness, whereas acute septic arthritis is often readily visible because the joint is red, tender, and swollen. Early diagnosis and prompt treatment remain pivotal in avoiding complications in acute bacterial bone and joint infections.