Background: This study aims to increase understanding of how patient and family education affects the prevention of medical errors, thereby providing basic data for developing educational contents. Methods: This descriptive study surveyed patients, families, and Patient Safety Officers to investigate the relationship between educational contents and medical error prevention. The Chi-square test and ANOVA were used to derive the results of this study. The educational contents used in this study consisted of health information (1. current medicines, 2. allergies, 3. health history, 4. previous treatments/tests and complications associated with them) and Speak Up (1. handwashing, 2. patient identification, 3. asking about medical conditions, 4. asking about test results, 5. asking about behaviour and changes in lifestyle, 6. asking about the care plan, 7. asking about medicines, and 8. asking about medicine interactions). Results: In this study, the first criterion for choosing a hospital for treatment in Korea was 'Hospital with a famous doctor' (58.6% patient; 57.7% families). Of the patients and their families surveyed, 82.2% responded that hospitals in Korea were safe. The most common education in hospitals is 'Describe your medical condition', given to 69.0% of patients, and 'Hospitalisation orientation', given to 63.4% of families. The most important factors in preventing patient safety events were statistically significant differences among patients, family members, and Patient Safety Officers (p = 0.001). Patients and families had the highest 'Patient and family participation' (31.0% of patients; 39.4% of families) and Patient Safety Officers had the highest 'Patient safety culture' (47.8%). Conclusions: Participants thought that educational contents developed through this study could prevent medical errors. The results of this study are expected to provide basic data for national patient safety campaigns and standardised educational content development to prevent medical errors.