Objective To explore the diagnosis and treatment of benign paroxysmal positional vertigo (BPPV) with bilateral posterior canal involved. Methods The clinical data of BPPV patients, who were diagnosed in the Dizziness Clinic of Changzheng Hospital from January 2012 to December 2012, were retrospectively analyzed. The patients had bilateral torsional upbeating geotropic nystagmus as showed by Dix-Hallpike test. The diagnosis and treatment strategies were summarized. Results Twenty patients presented bilateral torsional upbeating geotropic nystagmus in Dix-Hallpike test; further investigation by lean and bow test showed that six patients manifested with vertical upbeating nystagmus in lean test and no nystagmus was found in the bow test; then they were diagnosed as having bilateral posterior canal BPPV and were treated by bilateral particle repositioning maneuver. Whereas the torsional upbeating nystagmus remained in the other 14 patients in both lean and bow test, but the torsional direction of nystagmus was reversed, so these patients were diagnosed as having unilateral horizontal canal BPPV and their symptoms disappeared after treated by unilateral Barbecue maneuver. Conclusion Diagnosis of bilateral posterior canal BPPV should not be hastily made in patients showing bilateral torsional upbeating geotropic nystagmus in Dix-Hallpike test unless unilateral horizontal canal BPPV is ruled out.