Aim: To determine correlations for nurse self-reported occupational stress, prevalence of cognitive failure (CF), and adverse events. Design: Cross-sectional nationwide survey. Methods: Tertiary-level public hospitals (N = 115) from 13 provinces in Iran were recruited and 2,895 nurses surveyed (August 2016–December 2017). Participants’ self-reported demographic information, occupational stress, CF, and frequency of adverse events were analysed using chi-square, t tests, and binary logistic regression. Results: This study showed that 29.1% of nurses had experienced adverse events in the past six months. Significant predictors for reported adverse events from logistic regression were ‘Role stressors’, ‘Interpersonal relations stressors’, and ‘Action’, while ‘Working environment stressors’ was protective for reported adverse events. Demographic predictors of adverse events were longer work hours and male gender, while those working in critical care units, general wards, and other wards had higher reported adverse events than for emergency wards. Conclusions: Occupational stress and CF are associated with the reporting of adverse events. Further research is needed to assess interventions to address occupational stress and CF to reduce adverse events. Impact: Adverse events compromise patient safety, lead to increased healthcare costs, and impact nursing staff. Higher self-reported adverse events were associated with higher reported stressors and CF. Understanding the factors that influence occupational stress, CF, and adverse events will support quality patient care and safety