Abstract: OBJECTIVE To analyze potential adverse drug interactions of antibacterial drugs in hospital outpatients from 2020 to 2023. METHODS A cross-sectional study was conducted on outpatients treated with antibacterial drugs at Sun Simiao Hospital of Beijing University of Chinese Medicine. The occurrence and risk of potential drug interactions of antibacterial drugs in outpatients were observed annually, and their severity and clinical significance were analyzed. Specific intervention recommendations were proposed accordingly. RESULTS From 2020 to 2023, a total of 9 133 outpatients received antibacterial drugs, among whom 813 experienced at least one potential antibacterial drug interaction, yielding an incidence rate of 8.90%. The annual incidence rates were 10.19%, 8.83%, 9.11% and 7.92%, respectively. Patients with potential antibacterial drug interactions had a higher proportion of ≥2 underlying diseases and a greater average number of drug types used than those without interactions(P＜ 0.05). Clinical pharmacists reviewed 13 527 medication orders and identified 813 potential antibacterial drug interactions, with 12 combinations being more common. The most frequently involved antibacterial drugs were quinolones, clarithromycin, oral cephalosporins and itraconazole. Potential antibacterial drug interactions often occurred after antibacterial drug treatment for infections in the skin and soft tissues, lungs, oral cavity and urinary tract. Common pharmaceutical recommendations included monitoring drug efficacy or toxicity, employing alternative medications, avoiding concomitant use and adjusting dosing intervals. CONCLUSIONS The incidence rate of potential adverse antibacterial drug interactions in hospital outpatients is high. Clinical pharmacists should prioritize monitoring and prevention to enhance the safety of antibacterial drug use in outpatients.