© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.Aim: Assessment of Oral Health Impact Profile (OHIP-14) during a randomized controlled trial of supportive periodontal therapy (SPT) consisting of oral prophylaxis with oral hygiene instructions only (test) or in conjunction with subgingival instrumentation (control). Methods: OHIP-14 was assessed at baseline, 6, 12, 18 and 24 months. Data from 62 participants (50.97 ± 9.26 years, 24 smokers) were analysed by GEE and Logistic regression. OHIP-14 means, effect size, floor and ceiling effect and minimal important difference were calculated. Sum of OHIP-14 (severity), numbers of responses (extent) “fairly often” (FO) or “very often” (VO) and percentage of people (prevalence) reporting FO or VO were computed. Results: At baseline, low scores of OHIP-14 were observed for test (7.67 ± 9.27) and control (6.51 ± 7.47) with a decreasing trend during SPT, without differences between or intra-groups over time. At 6 months, a difference was observed in the OHIP-14 prevalence (p =.03), without differences in severity and extent. Smoking status and plaque >15% (moderate oral hygiene) at 24 months were associated with higher OHIP-14 prevalence scores at that point of time (p =.038 and p =.034, respectively). Conclusion: Patients submitted to two different modalities of SPT maintained low OHIP-14 scores over 2 years of care.