Background Establishing a positive safety-culture environment is essential in healthcare settings to enhance patient care. This study aimed to determine the relationship between critical care nurses’ perceptions of patient safety culture and adverse events. Methods A cross-sectional study was conducted among 200 nurses working in critical care units in the Damanhour Governorate in Egypt. Data were collected using a self-administered questionnaire, including the Hospital Survey of Patients’ Safety Culture (HSOPSC) and information on adverse events (AEs). Results The study revealed areas for improvement in patient safety culture, with low positive response rates in staffing (26.6%), non-punitive response to errors (38%), handoffs and transitions (39.4%), teamwork across and within units (42.3%), and overall perception of patient safety (49.3%). The majority of critical care nurses had a moderate to high level of overall perception of patient safety at 42.5% and 42.0%, respectively. The most frequent adverse events reported daily were complaints from patients or their families (65.5%). Adverse drug events and patient falls occurred several times per week in 56.5% and 57.0% of patients, respectively. A significant association was found between low safety culture perception and higher rates of patient falls ( p = .008), adverse drug events (p = .005), and patient/family complaints (p = .030). Conclusion The findings of the study indicate that nurses’ perceptions of patient safety culture are moderate. Adverse medication responses, falls, and complaints from patients or their families were noted. Female nurses aged 31 to 40, especially divorced nurses, had more experience, worked fewer than 8 h daily, and had a higher education level, which appeared to influence overall safety culture perceptions. Furthermore, there was a correlation between the prevalence of adverse events and patient safety culture, with cooperation being the key factor.