Maintaining good oral hygiene in patients wearing fixed appliances is a challenge for orthodontics. Conventional education has been demonstrated to be insufficient for the promotion of good oral habits, while motivational interviewing has the potential to facilitate health behavior change. The present randomized controlled trial with 130 patients aimed to evaluate the effectiveness of a single session of motivational interviewing in enhancing oral hygiene in orthodontic patients compared with conventional education alone. Results revealed an immediate improvement in oral hygiene which remained stable throughout the 6-month follow-up.