The treatment of posterior canal benign paroxysmal positional vertigo often involves repositioning maneuvers and exercises; however, these procedures may not be suitable for patients with limb disabilities or back disorders, or for elder patients. We sought to develop a simple therapeutic maneuver as an alternative procedure, suitable for patients with a wide range of physical ability. A simple therapeutic maneuver, supine to prolonged lateral position, was developed based on the mechanism of canalolithiasis. Its efficacy in treating posterior canal benign paroxysmal positional vertigo was evaluated in a prospective study consisting of 81 objective and 13 subjective posterior canal benign paroxysmal positional vertigo patients. A successful outcome was defined as a negative Dix-Hallpike test within 2 weeks followed by the continued absence of symptoms of vertigo or dizziness for the next 4 weeks. Seventy-two patients with objective posterior canal benign paroxysmal positional vertigo and all 13 patients with subjective posterior canal benign paroxysmal positional vertigo were successfully treated: resolution rates were 88.9 and 100 %, respectively. In the objective group, negative Dix-Hallpike tests were obtained at 1 and 2 weeks in 66.7 and 88.9 % of patients, respectively. In the subjective group, the percentages of patients free of side-dependent vertigo illusions at 1 and 2 weeks were 84.6 and 100 %, respectively. These results suggest that the supine to prolonged lateral position maneuver, which is easy to perform and generally well tolerated, could be recommended as an alternative treatment modality for patients with posterior canal benign paroxysmal positional vertigo.