<b><i>Aim:</i></b> The main objective of this study was to evaluate the association of mediolateral episiotomy with severe perineal trauma during Kiwi omnicup vacuum delivery. <b><i>Methods:</i></b> This retrospective study analyzed all Kiwi omnicup vacuum deliveries between 2010 and 2015 in nulliparous women. Secondary outcomes of interest included frequency of genital tract trauma, outcome of Kiwi extraction and influence on neonatal parameters. <b><i>Results:</i></b> A total of 572 nulliparous women who were delivered with the aid of vacuum were analyzed. Successful completion of birth was achieved in 549/572 (96%) resulting in a failure rate of 4%. Out of 572 women, 372 (65%) underwent the Kiwi vacuum delivery system in conjunction with episiotomy. Third- or fourth-degree perineal tears occurred in 38 out of the 572 (6.6%) women and the rate of severe perineal trauma was statistically and significantly lower in women who delivered with the aid of the Kiwi vacuum in conjunction with episiotomy (<i>p</i> = 0.0001). Besides, perineal tears of all degrees, vaginal tears and labial trauma were significantly less common in the Kiwi vacuum delivery system when combined with mediolateral episiotomy (<i>p</i> = 0.0001, <i>p</i> = 0.006, and <i>p</i> = 0.0001, respectively). <b><i>Conclusion:</i></b> Our data showed that the performance of a mediolateral episiotomy was associated with a decreased risk of severe perineal tears as well as vaginal and labial trauma in Kiwi omnicup vacuum deliveries.