Active audiovisual representation of instructions ensures vibrant knowledge acquisition and improves acquaintance needed for self-care with retainer wear. The aim of this trial is to assess the impact of audiovisual instructions with additional weekly electronic reminder messages on improving adherence to instructed wear time of Hawley retainer, periodontal outcomes, and participants' experiences. Fifty-two participants (mean age 26.1 y) planned for removable retention, were randomly assigned to two parallel groups to receive either (1) audiovisual instructions with an additional weekly reminder, or (2) verbal instructions alone. Each participant received a Hawley retainer equipped with a TheraMon microsensor and was instructed to wear it for 22 h daily. Participants were monitored for adherence to the wear time after 3 (T1) and 6 months (T2), and had their periodontal health and experiences assessed at T2. Overall, the mean objectively measured daily wear time at T1 was 14.9 (± 4.9 h), and 14.3 (± 5.4 h) at T2. After 3 months, no significant differences were found between the groups (p = 0.065), however, a significant difference favoring better compliance with wear instructions was observed in the audiovisual group after 6 months (p = 0.033). A non-significant difference was observed between both groups regarding the gingival (p = 0.165) and plaque index scores (p = 0.173). Participants' experiences were similar in both groups, except for satisfaction with the way of delivering instructions, being favorably reported in the audiovisual group. Audiovisual instructions with weekly reminders seem to have a significant effect on patient compliance in the longer term.Trial registration: TCTR20230220002.