Obstructive sleep apnea (OSA) tends to worsen on the supine posture due to the effect of gravity on tongue position. In some cases, OSA is present exclusively on the supine posture (exclusive postural OSA). These patients may benefit from positional therapy (PT), which aim is to prevent sleep in the supine posture using different types of devices. Before opting for this therapeutic option, a sleep study with PT should be perform in order to confirm its efficacy and assess the patients' tolerance. Because the efficacy of PT is inferior to continuous positive airway pressure (CPAP), the latter treatment remains the first line of therapy. Also, the discomfort of the existing devices appears to limit the long term use of PT. Further studies assessing the long term effects of PT on metabolic and neurocognitive outcomes are needed.