ObjectiveTo assess the effectiveness of vaginal diazepam in addition to transcutaneous electrical nerve stimulation (TENS) in the treatment of vestibulodynia (VBD). Study DesignThis study was a randomized, double-blind, placebo-controlled trial. Forty-two patients with VBD were randomized, 21 underwent diazepam and TENS (diazepam group) and 21 received placebo and TENS (placebo group). Vulvar pain was assessed on a on a 10-cm visual analogue scale (VAS) and dyspareunia according to the Marinoff dyspareunia scale. Vaginal surface electromyography (EMG) and vestibular current perception threshold (CPT) testing were performed at baseline and 60 days after treatment. The primary endpoints included the change in pain and dyspareunia from baseline to 60 days of pain and dyspareunia. The secondary endpoints was the variation in objectivity of pelvic floor muscle (PFM) function and vestibular nerve fiber current perception threshold (CPT). ResultsThe VAS scores for pain from basal values of 7.5 and 7.2 for the diazepam and placebo, respectively, showed significant (p 0.01) decreases from 4.7 to 4.3, but this difference was not statistically significant. The Marinoff dyspareunia scores in the diazepam group showed a significant difference (p 0.05) from values measured in the placebo group. The ability to relax the PFM after contraction (difference between maximal contraction and rest tone) was significantly greater for the diazepam group versus the placebo group (3.8 μv and 2.4 μv, respectively, p 0.01). The CPT values for all of the nerve fibers increased after the treatment, but this increase was significant in the diazepam group only for the values at a 5-Hz stimulation (C fibers) with a change of 47.8% vs 26.9% (p < 0.05). Only two patients reported a mild drowsiness in the diazepam group. ConclusionsThe present study provided indications that vaginal diazepam plus TENS is useful to improve pain and PFM instability in women with VBD.