Rhinosinusitis is one of the most common conditions for which patients seek medical care. Subtypes of rhinosinusitis include acute, subacute, recurrent acute, and chronic. Acute rhinosinusitis is further specified as bacterial or viral. Most cases of acute rhinosinusitis are caused by viral infections associated with the common cold. Symptomatic treatment with analgesics, decongestants, and saline nasal irrigation is appropriate in patients who present with nonsevere symptoms (e.g., mild pain, temperature less than 101°F [38.3°C]). Narrow-spectrum antibiotics, such as amoxicillin or trimethoprim/sulfamethoxazole, are recommended in patients with symptoms or signs of acute rhinosinusitis that do not improve after seven days, or that worsen at any time. Limited evidence supports the use of intranasal corticosteroids in patients with acute rhinosinusitis. Radiographic imaging is not recommended in the evaluation of uncomplicated acute rhinosinusitis. Computed tomography of the sinuses should not be used for routine evaluation, although it may be used to define anatomic abnormalities and evaluate patients with suspected complications of acute bacterial rhinosinusitis. Rare complications of acute bacterial rhinosinusitis include orbital, intracranial, and bony involvement. If symptoms persist or progress after maximal medical therapy, and if computed tomography shows evidence of sinus disease, referral to an otolaryngologist is warranted.