This study was descriptive research using both qualitative and quantitative methods. The “CIPP Model” was used as a conceptual framework. The aims of the study were 1) to evaluate the structure of ARI Clinics; 2) to evaluate the process of setting up ARI Clinics; 3) to evaluate the outcomes of ARI Clinics; 4) to synthesize knowledge of COVID-19 screening and management to improve ARI Clinics’ services. Data for the qualitative method were collected by in-depth interviewing using semi-structured questions and document analysis. This study recruited physician executive directors, nurse administrators, health care providers who worked at the ARI clinics, and clients who attended ARI clinics. Samples selected. The persons with a high risk for coronavirus infection who attended the ARI clinics were recruited in a quantitative method. Data were collected by 4 questionnaires including questionnaires for personal information, anxiety numeric rating scale, self-care competency, and satisfaction with ARI clinic service. The content validity indexes of the self-care competency questionnaire and the satisfaction for the ARI clinic service questionnaire were 1 and .93, respectively. The reliability of two instruments was tested in 30 clients who were not included in the study. The Cronbach’s coefficients were .78 and .84, respectively. The study respondents included 350 clients who attended the ARI clinics between September and November 2021. Data were collected from August to November 2021. Content analysis was used for analyzing qualitative data. Descriptive statistics were used for quantitative data. Results of the qualitative part showed that the operation of Acute Respiratory Infection (ARI) Clinics for COVID-19 screening and management at Ramathibodi hospital could be described in three aspects as follow. 1)Structure of the ARI clinics showed that the services of ARI clinics at Ramathibodi hospital had an appropriate structure corresponding with organizational context and policy in COVID-19 prevention and control. Teamwork and employee engagement were encouraging and used to develop and improve the quality and the feasibility of the services. These mechanisms were used to help people, healthcare personnel, and society. The hospital administrators have supported academic information, resources, and welfare appropriately and continuously. The developmental process was adequate. Moreover, the staff understood the principle and guidelines of infection control. Shared resources by rotating medical staff from all related units. The advantages of the ARI clinics at Ramathibodi hospital were IT development including application and software called Rama Care to reduce workload and risk. 2)Evaluation of the process showed that adequately updated information was provided to increase knowledge and skills for staff working at the ARI clinics. The original administration structure was applied for setting the master plan, workflow, roles, and responsibilities in managing the ARI clinics. Health care service systems and working processes were operated by the infectious control department. All units had regular meetings to evaluate the ARI clinic's operation and improve the working process. The medical resources preparation and staff training were performed. Rama Care was introduced to related persons. The cleaning staff was also trained in infection control. The steps of service (screening-swab-report-refer-follow up) were followed. ARI clinics at Ramathibodi hospital and Ramathibodi Chakri Naruebodindra Medical Institute have the same working process including 1) One-Stop Service 2) Fast track 3) One-way flow and 4) Modular swab unit which followed the standard guidelines from the Department of Disease Control, Ministry of Public Health. 3) Evaluation of outcomes is divided into two parts. 1) Output: It was reported that 58,395 persons attended the ARI clinics between March and September 2021, 54,207 of them were patients under investigation (PUI) for COVID-19 (92.83%), and 53,583 suspected persons were performed RT-PCR tests (98.85%). All COVID-19 cases were treated and followed by phone. 2) Outcome: The 350 respondents who attended the ARI clinics were included in the quantitative and qualitative analyses. The average age of the respondents was 35.74 years (SD 14.27). Most of them were female 74.6%, graduate study 48.6%, single 58.6%. The reasons that recipients attended the ARI clinics were because they contacted the patients confirmed with COVID-19 48.6%. The underlying diseases were allergic rhinitis and asthma 11.7%, hypertension, and diabetes mellitus 8%. About 44.9% reporting that they had anxiety at a moderate level (Mean 5.20, SD 2.63, ranging from 0-10). About 89.4% of them had a high level of self-care competency (Mean 30.35, SD 4.78, ranging from 9-36). Most of the respondents (96.0%) were satisfied with the ARI clinic service at a high level (Mean 68.95, SD 7.49, ranging from 34-75). In conclusion, the evaluation of ARI clinics at Ramathibodi hospital showed several advantages in the services of the ARI clinic clients. The results are suggested to use as the model development for setting ARI clinics. The clients would receive the best care. Both healthcare providers and receivers would be safe from the infection. The prompt and continuous services would increase clients’ satisfaction. The organization should readily prepare for respiratory infections disease or emerging diseases.