Background: The COVID-19 pandemic had a significant global impact, and although it has been controlled at the moment, the possibility of a resurgence is remains high if appropriate preventive measures are taken. Da Nang was one of the largest cities where the epidemic broke out and spread intensively in Vietnam. Knowledge, attitudes, and practices (KAP) towards COVID-19 play an important role in controlling and preventing the disease. Objectives: To evaluate the KAP toward COVID-19 prevention among patients who visit to Da Nang Hospital for examinations and identify some related factors. Methods: A cross-sectional study was conducted on 350 patients who visited the Department of Medical Examination of DaNang Hospital from November 2022 to April 2023. The questionnaire assessing knowledge, attitude, and practice of COVID-19 prevention of patients with 30 items was used and revised with the permission of the original author. Chi-square tests and odds ratios (ORs) with a 95% confidence interval (CI) were used to identify factors related to patient characteristics and knowledge, attitude, and practices of COVID-19 prevention. The results were considered statistically significant when p < 0.05. Results: The percentage of participants with good knowledge, positive attitude, and successful practice on COVID-19 prevention accounted for 86.6%, 89.1%, and 56.3% respectively. Factors related to knowledge include sex (OR=1.88, 95% CI: 0.99-3.52, p-value < 0.05), age, education level, and family economy; attitudes include education level, place of residence (OR=0.44, 95% CI: 0.20-0.84, p-value < 0.05), occupation; and COVID-19 infection status (OR=0.47, 95% CI: 0.23-0.95, p <0.05); and practices include sex (OR=0.57, 95% CI: 0.37-0.88, p-value <0.05), age, education level , place of residence (OR= 0.65, 95% CI: 0.42-0.95, p-value <0.05) and occupation . Conclusion: Research results showed that patients who visit to Da Nang Hospital for examinations have a high level of good knowledge and a positive attitude, while successful practices in COVID-19 prevention were not high. Thus, it is still necessary to promote and improve patients' knowledge about disease prevention vaccines, as well as enhance the practice of washing hands and covering mouths when coughing and sneezing for better disease prevention.