Expiratory positive airway pressure (EPAP) nasal devices provide a new therapeutic option for obstructive sleep apnea (OSA). Here, we review the literature about treatment of OSA with EPAP, which has been shown to reduce the apnea/hypopnea index (AHI) and daytime sleepiness. Patients generally prefer EPAP to continuous positive airway pressure (CPAP), and there are no serious adverse effects from its use. Although CPAP more effectively improves sleep apnea, a recent study showed similar outcomes in symptom improvement using EPAP. Patients with mild to moderate OSA who do not tolerate CPAP are appropriate candidates for EPAP. However, there are few well-designed clinical trials that evaluate efficacy. More studies are needed to assess the efficacy of and compliance with EPAP nasal devices, to define which patients will benefit from EPAP therapy, and to compare EPAP to other alternative OSA therapies.