Introduction: The consequences of unused and expired medications encompass environmental contamination, increased global warming risks, wastage of public resources, as well as unintentional poisoning resulting from accidental ingestion. To facilitate the return of unused or excess medications by patients, the MoH in Malaysia has implemented the “Return YourMedicines Program”. The goal of this study was to assess the effectiveness of a pharmacist-led educational intervention in educating the public and enhancing the appropriate disposal of unused and expired medications. Methods: An interventional research study had been carried out for a duration of eleven months from October 2022 to August 2023. The respondents participated in this study via invitation from email, WhatsApp messages, and other social media platforms. All respondents had answered a pre-intervention questionnaire prior to the educational intervention, followed by seven days of educational intervention, as well as a final data collection on the seventh day. Results: The study successfully obtained 397 responses in pre-intervention, and 353 responses in post-intervention, thereby achieving a response rate of 89%. The knowledge score of the respondents had enhanced to a sufficient level from 44.4% to 91.2% upon completion of the educational intervention. Vitamins (Npre=194, 48.9%; Npost=222, 62.9%), and cough preparation (Npre=193, 48.6%; Npost=219, 62.0%) were the two most widely existing unused and/or expired medications before and after educational intervention. An excessive number of medications (Npre=230, 57.9%; Npost=215, 60.9%), and improvement in the illness condition (Npre=158, 39.8%; Npost=261, 73.9%) were known as the two most common reasons for having unused and/or expired medications before and after educational intervention. Approximately 90% of the respondents (n=317) would participate in the “Return Your Medicines Program” in managing unused and/or expired medications after receiving the educational intervention. Conclusion: The educational intervention demonstrated a positive impact in enhancing the knowledge, attitude, and practice regarding the safe disposal of unused and expired medications. Keywords: unused, expired, medications, effectiveness, intervention