PURPOSE: COVID-19 is a threat to health worldwide. For nursing students, it affects the physical, mental, social, and family economy. This research aimed to study the relationship between perceived self-efficacy, preventive health behaviors in COVID-19, and quality of life among nursing students during the COVID-19 pandemic. SAMPLES AND METHODS: This study was descriptive research. The samples included 273 nursing students by simple random sampling. The data was collected using a questionnaire about perceived self-efficacy, preventive health behaviors, and quality of life. The data were analyzed by descriptive statistics, chi-square, and binary logistic regression statistics. RESULTS: The mean score of perceived self-efficacy and preventive health behaviors against COVID-19 were high (M = 71.47, . = 8.46; M = 69.10, .= 8.72; respectively). The mean score of quality of life was also high (M = 97.69, .=13.62). In addition, it was found that perceived self-efficacy and preventive health behaviors were significantly related to quality of life among nursing students ( < 0.001). Confirmation with binary logistic regression found that perceived self-efficacy and preventive health behaviors were significantly related to the quality of life (OR = 2.87; 95% CI: 1.415.-5.85; OR = 3.39; 95% CI: 1.43-8.03; respectively) ( < 0.01). To clarify, the group with high perceived self-efficacy tended to have 2.87 times good quality of life than the group with low-moderate perceived self-efficacy. The group with high preventive health behaviors tended to have a 3.39 times good quality of life than the group with low-moderate preventive health behaviors. CONCLUSION: Well-perceived self-efficacy and preventive health behaviors against COVID-19 among nursing students were related to good quality of life. Therefore, their perceived self-efficacy should be promoted to build their confidence in the adjustment of preventive behaviors to be safe from COVID-19. This will lead to good quality of life among nursing students.