Objective <p>To evaluate the effectiveness of a simple sticker reminder in increasing intravenous-to-oral (IV-to-PO) fluoroquinolone (FQ) conversion rates.</p> Design <p>Single-center, cluster-randomized controlled trial.</p> Setting <p>Forty-five general wards at Siriraj Hospital, Bangkok, Thailand, from July 2020 through December 2024.</p> Patients <p>Hospitalized adult patients receiving intravenous fluoroquinolones who met predefined IV-to-PO conversion criteria.</p> Methods <p>Wards were randomized 1:1 to either a sticker reminder intervention or standard care. In the intervention group, a reminder sticker was placed on the vital signs sheet of eligible patients. The primary outcome was the proportion of IV-to-PO conversion in the intention-to-treat (ITT) and modified intention-to-treat (mITT) populations.</p> Results <p>A total of 168 patients were enrolled (85 intervention, 83 control). In the ITT population, the IV-to-PO conversion rate was 58.8% in the intervention group versus 42.2% in the control group (<i>p-value</i> = 0.03). In the mITT population (patients meeting all conversion criteria), the intervention group had a significantly higher conversion rate (69.0% vs. 48.5%; <i>p-value</i> = 0.01). No significant differences were observed in clinical cure rates, in-hospital mortality, length of stay, duration of either IV FQ or PO FQ therapy.</p> Conclusion <p>A sticker reminder intervention effectively increases IV-to-PO FQ conversion among eligible patients without compromising clinical safety. Future large-scale and qualitative studies are needed to further validate these benefits and explore prescriber hesitation.</p> Trial registration <p>ClinicalTrials.gov NCT07361185 (retrospectively registered on 22 January 2026).</p>