Objectives To evaluate the efficacy of motivational intervention in improving short- and long-term compliance with instructions for maintaining oral hygiene. Materials and methods The study included 20 adult patients (mean age 45 years) with periodontal disease (Periodontal Screening and Recording [PSR] scores 3/4). All received instructions for maintaining oral hygiene, with (n = 10) or without (n = 10) motivational interventions. Patients were interviewed at 1 and 4 months to assess compliance and self-perception. Results The follow-up revealed decreased gingival bleeding and improved oral hygiene indexes, but there were no changes in pocket depth or attachment loss after 4 months. There was an improvement in patients’ self-perception and perception of their oral hygiene, but it decreased over time. Discussion As showed in previous reports, motivational intervention is not effective in increasing long-term compliance with oral hygiene protocols, but it is very important for increasing short-term compliance. Conclusions The study shows that motivational interventions are effective if they are done regularly at short intervals of time. It would be interesting to assess clinical results and compliance with an experimental protocol that includes nonsurgical periodontal therapy.