The liberatory maneuver of Semont is an effective physical treatment for benign paroxysmal positional vertigo. It works because it causes otoconia to move out the posterior canal. The effectiveness of the maneuver is thought to be indicated by the appearance of a liberatory nystagmus. After the maneuver, patients are usually instructed to keep their heads erect for several days and not to lie on the pathologic side for about a week. Here we investigated the prognostic value of liberatory nystagmus and whether restrictions are necessary after treatment. Fifty-six patients with posterior canal benign paroxysmal positional vertigo underwent the Semont maneuver and were checked after 20 minutes, 24 hours, and 1 week. The patients were told that they could sleep or move as they pleased, without any particular precautions. We found that liberatory nystagmus had a high prognostic value and that it was not necessary for patients to avoid certain positions or movements after treatment.