Introduction: Patient safety is one of the critical and crucial health issues worldwide and in Oman. Limited studies were conducted in Oman regarding the predictors of patient safety culture and frequency of event reporting among critical care nurses Purpose: This study was conducted to explore to what extent fatigue, workload, and work environment predict patient safety culture and frequency of event reporting among critical care nurses in selected hospitals in Oman. Methods: A cross-sectional predictive design was used to collect data from 270 critical care nurses who were working in Sultan Qaboos University Hospital and Royal Hospital mpleted the self-administered questionnaire with response rate of 90%. Hospital Survey on Patient Safety Culture (HSOPSC), Fatigue Assessment Scale (FAS), Maslach Bumout Inventory-Human Services Survey (MBI-HSS), NASA task load index, and Practice Environment Scale of the Nursing Work Index (PES-NWI) were used. Descriptive analysis included the mean standard deviation, frequency and percentage Correlation analyses and regression analyses were also conducted. Results: Majority of participants was females (86%) and 62.6% of them had Bachelor degree in Nursing. Results of Pearson's correlation indicated that there was negative association between nurses' fatigue, emotional exhaustion, depersonalization and overall perception of patient safety culture (r = -0.24, 1 = -0.17, = -0.26, n = 270, p<0.001, respectively), and positive correlation between nurses' work environment and patient safety culture (r= 0.13, n=270, p <0.05). Also results indicated positive correlation between personal accomplishment and frequency of event reporting ( 0.13, n= 270, P <0.05). Results of parsimonious multiple regression model indicated that work environment and feedback and communication about error were predictors for overall perceptions of patient safety culture among critical care nurses in Oman and they accounted for 36.5% of the variance R = 0.365, F = 20.58, p < 0.01) in overall perception of patient safety culture. The parsimonious multiple regression model results for frequency of events reporting indicated that, feedback and communication about errors was predictor for frequency of events reporting among critical care nurses in Oman and they accounted for 21.4% of the vanance (R =0.214, F = 12.82, <0.01) in frequency of event reporting Conclusions: Utilization of this study finding by hospital administration is an imperative first step in creating a safer healthcare system, which can be followed by cause analyses and action plans to address systematic issues and improve patient safety culture and frequency of event reporting.