Almitrine bismesylate is a pharmacologically unique respiratory stimulant. It enhances respiration after both acute and chronic administration by acting as an agonist of peripheral chemoreceptors located on the carotid bodies. In comparison with traditional central-acting respiratory stimulants, almitrine has advantages of oral activity, prolonged duration of effect, and an improved adverse effect profile. Almitrine is generally well tolerated, with headache and minor gastrointestinal disturbances being the most frequently observed side effects. This investigational agent has been shown to increase arterial oxygen tension while decreasing arterial carbon dioxide tension in patients with chronic obstructive pulmonary disease both at rest and during exercise through increased ventilation and improved ventilation/perfusion matching. It may also prove useful in the treatment of nocturnal oxygen desaturation because of its ability to reduce the frequency and severity of nocturnal hypoxemia without impairing the quality of sleep. Additional research is needed to further define the role of almitrine in the relief of hypoxemia.