Background <p>Antibiotic resistance (ABR) is a growing public health issue, where non-adherence to antibiotics accelerates the development of resistance. Packaging-based nudge interventions may offer a low-cost and scalable solution. This pilot randomized controlled trial (RCT) assessed the feasibility of a visual storytelling sticker affixed to antibiotic packaging to improve antibiotic adherence in patients with uncomplicated urinary tract infections (UTIs).</p> Methods <p>A parallel two-arm pilot RCT was conducted across six tertiary-care hospitals between May and July 2025. Physician-confirmed uncomplicated UTI patients, prescribed with oral antibiotics, were randomized in a 1:1 manner to receive either antibiotics with a visual storytelling sticker (intervention) or standard care (control). Primary outcomes were feasibility metrics, including recruitment, retention, and intervention delivery fidelity. Antibiotic adherence, measured by pill count at the completion of treatment, was assessed as an exploratory outcome.</p> Results <p>Of the 120 patients approached, 114 were screened, and 84 were deemed eligible. Seventy patients consented, of whom 66 were randomized (33 per arm). The recruitment and retention rates were 61.4% and 84.8%, respectively, whereas the intervention delivery fidelity was 87.5%. Exploratory analysis showed a 14.3% improvement in adherence in the intervention group (63.3%, 95%CI 61.1–65.5) compared with the control group (49%, 95%CI 46.5–51.5), though the study was not powered to test effectiveness.</p> Conclusions <p>This pilot trial showed that a packaging-based visual storytelling sticker can be successfully integrated into antibiotic dispensing workflows. Preliminary adherence differences offer estimates to inform sample size and design of a larger, definitive RCT.</p> Trial registration <p>Chinese Clinical Trial Registry (ChiCTR), ChiCTR2500111346. Registered on 30 October 2025. Retrospectively registered.</p>