Reversal of nystagmus on returning to the upright sitting position from the Hallpike position is a common observation. However, its relevance as a predictor of a successful canal repositioning manoeuvre (CRM) is not known, hence this study. The retrospective study of video-nystagmography (VNG) recordings of 321 patients (age range 13 years to 92 years) with posterior canal BPPV set out to determine the incidence of upright positioning-related reverse nystagmus in the Dix-Hallpike test, and to assess the relationship between the presence of reverse nystagmus and prognosis of posterior canal BPPV. The default CRM of all patients was the Epley manoeuvre. The normal practice at the tertiary centre was to assess patients at two-to-four-day intervals and perform Epley until recovery was confirmed. Reverse nystagmus (RN) on upright positioning was observed in the majority of patients – 273 (85%) compared to 48 (15%) without reverse nystagmus. On face value, it appears the number of CRMs in both groups (RN+ and RN-) was not very different but, after the third CRM, cure was achieved in 98.8% and 89.8% in RN+ and RN- respectively with the majority resolving after the second attempt. Five and four CRMs were required in the reversal vs. no reversal groups. Statistically however, the authors reported a difference in favour of the RN+ group, ie. fewer CRMs. The number of CRMs was 1.32 ± 0.68 in the RN+ group and 1.81 ± 0.98 in the RN- group (p < 0.001). Overall recurrence rate of BPPV was 8.4% within 16.45 ± 8.44 months (3-30 months) but there were no group differences. The duration of nystagmus was also not different between the two groups. The authors concluded that in the absence of reverse nystagmus in upright positioning, more CRMs may be necessary. I am not entirely sure about this conclusion. Moreover, many clinicians proceed with CRM after a positive positional test without returning patients to the upright position but, for those who do as a matter of routine, it may be worth bearing in mind the prognostic feature of reverse nystagmus.