For patients with suspected flexor tenosynovitis, the mainstay of diagnosis is a thorough history and physical examination. The examination is guided by evaluating the patient for Kanavel’s four cardinal signs. Empiric antibiotics should be started immediately on diagnosis covering skin flora and gram-negative bacteria. Typically, surgery is required. Appropriate exposure is required for adequate treatment and incisions should be tailored to preserve areas of skin compromised from draining sinuses and abscess pressure. Diabetes mellitus and peripheral vascular disease place patients at higher risk of poor outcomes including stiffness and amputation; early administration of antibiotics is the intervention that correlates most closely with good outcomes.