Background: Prospective audit and feedback is a method that allows the antimicrobial stewardship program (ASP) team to interact with attending physicians to tailor antibiotic therapy, including de-escalation, as appropriate. This study aimed to evaluate the acceptance and outcomes of ASP de-escalation recommendations in children who received meropenem. Methods: A prospective cohort study was conducted in children aged 1 month to 18 years who received meropenem in a tertiary-care teaching hospital. The ASP team gave recommendation between 72 and 120 h after initiating meropenem therapy. Acceptance of de-escalation recommendations among primary physicians was evaluated within 24 h of recommendation. Outcomes included clinical success rate on the 7th day and incidence rate of acquisition of carbapenem-resistant gram-negative bacteria (CR-GNB) within 30 days. Results: From March to December 2019, 217 children with a median (interquartile range) age of 2.1 (0.6, 9.5) years received meropenem. The ASP team gave recommendations in 127 (58.5%) of cases for continuation of meropenem therapy and 90 (41.5%) of cases for de-escalation. The overall acceptance of ASP de-escalation recommendations was 57.8% (95%CI: 46.9-68.1%). Clinical success rates were 85.2% in the accepted group compared to 77.5% in the rejected group (P = 0.06). The incidence rate of acquisition of CR-GNB within 30 days after treatment was 5.8% in the accepted group and 15.8% in the rejected group (P = 0.03). Conclusions: About half of the recommendations to de-escalate meropenem prescriptions were accepted through the ASP intervention. Carbapenem-resistant gram-negative bacteria acquisitions was less likely in the de-escalation group. A robust de-escalation strategy 72 h following carbapenem initiation should be encouraged to combat multidrug-resistant organisms.Key words acceptance, antimicrobial stewardship program (asp), meropenem, pediatrics, prospective audit and feedback.Antimicrobial resistance is a major threats to global health with multiple adverse outcomes including increasing length of hospital stays, increasing the cost of treatments, and increasing the risk of fatalities. In Southeast Asia, many hospitals report high rates of gram-negative bacterial (GNB) infection, especially multidrug-resistant (MDR) GNB. [1][2][3] In 2020, the national antimicrobial resistance surveillance center of Thailand reported that, among hospitalized children and the adults, 50.4% of Enterobacteriaceae bacteria were extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae, 10.6% were carbapenem-resistant Enterobacteriaceae (CRE), and 72.5% of Acinetobacter spp. were carbapenem resistant. 4 MDR-GNB are important because they cause both community-and hospital-acquired infections in pediatric patients, for which carbapenem is required for treatment. [5][6][7] Meropenem is a broad-spectrum antibiotic in the carbapenem group that can be used as empiric treatment in patients with severe infections and those at risk of MDR-GNB infections. 8 However, excessive...