The necessity of postural restriction to patients suffering from benign paroxysmal positional vertigo is controversial. To investigate the impact of the sleep position after the repositioning maneuver on BPPV recurrence. 150 unilateral BPPV patients who were treated by repositioning maneuver were distributed into two groups. The patients in group A were instructed to sleep in a semi-sitting position at an angle of approximately 30 degrees and refrain from sleeping on their BPPV affected side for one week. The patients in group B were told to sleep in any preferred position. The comparison of recurrence rates according to different actual sleep positions in one week and one month was performed. There was a statistically significant correlation between the sleeping side and the side affected by BPPV. Without instructions on postural restriction, most patients (82.9%, 73/88) avoided sleeping on their affected side. The patients sleeping on their affected side had a higher recurrence rate (35.3%) than ones sleeping in other positions in the first week after the repositioning maneuver (p<0.05, Chi-square test and Fisher's exact test). The patients sleeping randomly in following 3 weeks had a lower recurrence rate than ones sleeping in other position (p<0.05, Fisher's exact test). BPPV patients had a poor compliance to postural instructions. The habitual sleep side was associated with the side affected by BPPV. The patients sleeping on their affected side had a higher recurrence rate than those sleeping in other positions in first week after the repositioning maneuver.