Background: Despite improving the quality of health services and developing methods of infection prevention and control, the occurrence of nosocomial infections remains a health threat to patients and hospital staff. This study applied Social-Cognitive Theory for predicting determinants of Nosocomial Infections Control Behaviors in hospital nursing Staff.Methods: In this cross-sectional study, 280 nurses and assistant nurses were selected by random sampling from intensive care wards including CCU, ICU, NICU, dialysis of educational hospitals in Mashhad, Iran in 2020. Data were collected using a 5-point Likert scale structural questionnaire based on social cognitive theory constructs and analyzed via AMOS 23.0 using Structural Equation modeling approach.Results: The results of the structural equation model showed that the constructs of barriers, perceived environment, outcome expectations, task self-efficacy, social support, and modeling were able to predict 70% of the variance of self-regulation construct. Also, the constructs of this social-cognitive model were eventually able to predict 15% of the variance of behavior construct. Self-regulation, outcome expectations, and barrier constructs had a direct effect on behavior and the highest effect was related to self-regulation structure (p<0.001). The constructs of social support, modeling, perceived environment and Task self-efficacy had an indirect effect on behavior and the most impact was related to the constructs of perceived environment (p<0.05). Conclusion: Considering that self-regulation, outcome expectation and barriers have a significant effect on following the preventive behaviors of nosocomial infections in nursing staff. It is suggested that policymakers and planners try to reduce barriers, strengthen behavioral motivation, and empower nursing staff by teaching self-regulatory strategies.