Suppurative tenosynovitis and septic bursitis are closed space infections of the musculoskeletal system. Appropriate antibiotics in combination with incision and drainage are generally recommended. Aggressive surgical management is particularly important in tenosynovitis to prevent tendon necrosis. Empiric antibiotic coverage should be directed toward staphylococci and streptococci. Patient characteristics and epidemiologic exposures may provide clues to unusual causative organisms that are occasionally encountered, such as Neisseria gonorrhoeae, Pasteurella multocida, atypical mycobacteria, fungi, and protothecosis.