BACKGROUND: Urinary tract infections are common and lead to frequent and inappropriate antibiotic prescribing in primary care. The RedAres randomized controlled trial has shown to reduce second-line antibiotic use for urinary tract infections through a multimodal intervention. It included guideline recommendations for general practitioners and patients (1), provision of regional data for antibiotic resistance (2), delivering personalized feedback based on the proportion of first- and second-line antibiotic prescriptions (3), and benchmarking with regional or supra-regional practices (4). To discuss all interventions, individual telephone counselling was offered. The aim of the RedAres process evaluation is to assess the acceptability of the multimodal intervention among general practitioners and the feasibility of the study design for medical practice assistants. METHODS: The general practitioners and medical practice assistants surveys were conducted following the RedAres intervention during the last trial visit. To assess acceptability among general practitioners, we developed a questionnaire based on Sekhon´s theoretical framework of acceptability. The questionnaires for medical practice assistants included questions on data management feasibility and attitudes towards this task. Data were analyzed using SPSS and R. Cases were weighted according to the number of respondents per practice, descriptive statistics, chi-squared tests, bivariable logistic regressions, and multivariable logistic regressions were used for data analysis. RESULTS: The response rate to the questionnaires was 96.6% for general practitioners ( = 63) and 91.5% for medical practice assistants ( = 56). Most general practitioners (93.9%) found the multimodal intervention to be adequate for enhancing guideline adherence. Among the intervention components, resistance data (31.8%) and prescribing feedback (31.8%) were equally appreciated, while benchmarking (12.2%) was the least appreciated intervention. Most medical practice assistants (96.3%) reported being satisfied with the data collection, documentation, and transfer in the RedAres study. CONCLUSIONS: The RedAres intervention was favorably received by general practitioners, medical practice assistants deemed data management and extraction feasible. With the backdrop of the intervention’s effectiveness, its favorable reception, and its practicability, antibiotic stewardship and quality control measures implemented at the practice level hold promise for effectively enhancing guideline adherence and improving antibiotic stewardship practices in real-world settings. TRIAL REGISTRATION: Prospective registration at the German Clinical Trial Register (DRKS), trial number DRKS00020389, registration date 30.01.2020 (https//drks.de/search/en/trial/DRKS00020389). SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12913-025-13218-2.