Several drugs have been described as possible treatments for Sleep Apnea/Hypopnea Syndrome (SAHS) but the data available does not support their use. In an animal model of central apnea the use of mirtazapine produced a significant reduction of apneas. We present a male patient, 82 years old, with excessive daytime sleepiness and loud snoring during at least 10 years. An overnight polysomnography (PSG) revealed an apnea/hypopnea index of 54.9 events per hour of sleep with a minimum pulse oximetric saturation (SaO(2)) of 78% and an arousal index of 40.4 per hour. A nasal CPAP titration in the second half of the night showed suppression of apneas with a CPAP level of 8 cmH(2)O. The patient refused to use the CPAP device and began with 15 mg of mirtazapine at bedtime. A second PSG performed after 3 months of mirtazapine showed a significant reduction in the apnea/hypopnea index (9.3 events per hour of sleep; 81% minimal oxygen saturation (SaO(2))). Clinically, the patient and his wife reported a clear reduction of excessive daytime sleepiness and an improvement in self-reported functioning and well-being without any important side effects. This successful case appears to be the first report with mirtazapine in human SAHS and supports the need for an appropriate clinical trial with this drug.