Purpose: In the present randomised controlled trial (RCT), the authors hypothesise that herbal-based oral rinses are as effective as 0.12% chlorhexidine when used as adjuncts to non-surgical mechanical debridement (MD) in the management of peri-implant mucositis. The aim of the present RCT was to compare the efficacy of an herbal oral rinse with a 0.12% chlorhexidine-based oral rinse when used as adjuncts to non-surgical MD in the treatment of peri-implant mucositis. Materials and Methods: Adult patients with peri-implant mucositis were included. Participants were randomly allocated into 3 groups. In group 1, patients only underwent non-surgical MD. In groups 2 and 3, patients underwent non-surgical MD with adjunct rinsing with an herbal- and 0.12% CHX-based oral rinse, respectively. Peri-implant plaque index (PI) and bleeding-on-probing (BOP) and probing-depth (PD) were assessed at baseline and at 3, 6, and 12 weeks. Group comparisons were done and p 0.01 was considered statistically significant. Results: Forty-eight patients with peri-implant mucositis (16, 16, and 16 in groups 1, 2 and 3, respectively) were included. At baseline, there was no difference in PI, PD, BOP in all groups. In group 1, there was no statistically significant difference in PI and BOP at 6, and 12 weeks of follow-up compared with baseline. In groups 2 and 3, PI (p 0.01) and BOP (p 0.01) were statistically significantly higher at baseline than 3, 6, and 12 weeks of follow-up. In group 1, there was no statistically significant difference in PD at all time intervals. In groups 2 and 3, PD was statistically significantly higher at baseline than 3, 6, and 12 weeks of follow-up. In groups 2 and 3, there was no statistically significant difference in PI, BOP and PD at all intervals. Conclusion: Herbal- and 0.12% CHX-based oral rinses are useful adjuncts to MD for the treatment of peri-implant mucositis. Schlagwörter: bleeding on probing, chlorhexidine, herbal, peri-implant mucositis, probing depth