Purpose: Obstructive sleep apnea (OSA) is a treatable global health concern with increasing prevalence, driven by the obesity epidemic and the aging population. Unfortunately, approximately one-third of patients are non-adherent to long-term treatment. This highlights the importance of identifying those with positional obstructive sleep apnea (POSA), which affects 25%-35% of the OSA population, as these patients may benefit from alternative therapeutic interventions such as vibrating positional devices or positional pillows. The aim of this prospective randomized crossover study was to assess the efficacy of two different positional therapies (PTs): a positional pillow (Posiform®) and a vibrating belt (Somnofit-belt®), for reducing supine sleep time in POSA patients in the home setting. Methods: Adults with POSA (n=102), diagnosed by polysomnography (PSG) at two university hospitals, were screened, and 19 patients met the criteria for at-home supine sleep and were included. Patients were randomized to use either the vibrating belt first and then the pillow, or the reverse. Patient questionnaires were used to assess sleep quality and comfort, and the Somnibel Pro® device was used to assess patients’ sleep position. Results: A statistically significant reduction in supine sleep time was observed in patients using the vibrating belt compared to baseline (p = 0.0001). No difference was observed for the pillow. There was no significant difference in sleep quality or comfort between the devices. This study also highlights the observation that supine sleep is infrequent in the home setting. Conclusions: In this study, we have shown a significant reduction in supine sleep time in POSA patients using the vibrating belt, which was not observed with the positional pillow. However, the results must be qualified by the small number of patients included.