Aims and objectives: To identify and examine the relationship between the factors influencing the decision-making ability of clinical nurses in hospitals, South Korea, and to establish a model, to verify the fit and the effect.Background: Clinical nurses are exposed to environments and situations where they make continuous decisions according to the need of direct treatment and nursing.Design: This study used a cross-sectional descriptive design, relation prediction modelling and adheres to the STROBE guidelines. Methods:The model construction was based on the information processing theory by Hansen and Thomas (Nursing Research, 17, 436, 1968). The model consists of 5 exogenous variables (expertise, critical thinking disposition, knowledge-sharing behaviour, nursing work environment, and decision-making stress) and 3 endogenous variables (analytic-systematic decision-making type, intuitive-interpretive decisionmaking type and decision-making ability). Participants were 274 clinical nurses, who were working at two hospitals in Seoul, South Korea. The data was analysed using SPSS WIN 18.0 and AMOS 20.0 program. Path analysis to verify the hypothetical model was used, and the fit was evaluated by χ 2 /df, GFI, AGFI, NFI, CFI and RMSEA.Data were collected from March to May 2017. Results:The fit index of the modified path model was χ 2 /df = 2.25, GFI = .972, AGFI = .929, NFI = .967, CFI = .981 and RMSEA = .068. The analytic-systematic decision-making type had the greatest direct effect on the clinical nurses' decisionmaking ability, which is the final outcome variable, followed by significant direct and indirect effects on critical thinking disposition. Conclusion:This study suggests that the clinical nurses' decision-making ability in hospitals were leadingly influenced by analytic-systematic decision-making type and critical thinking disposition. Relevance to clinical practice:In the nursing practice, nurses need to pay attention the analytic-systematic decision-making type and critical thinking disposition for improving decision-making ability of clinical nurses in hospitals.