Background: In today competitive world, human work force has always been a concern for organizations, especially healthcare providers, and organizations are always looking for improving their employees' job performance. Among various factors affecting job performance are two factors of organization and personality traits of the workforce. Therefore, the aim of this study was to investigate the relationship between five personality traits of nurses and the organization knowledge of their job performance.
 Methods: This is an analytical study conducted in a cross sectional way in 2016. Sixty one nurses working in a traumatic hospital proportional to different wards were selected and entered the research. The instruments for collecting data were three organizational knowledge questionnaires (35 items), five personality traits (60 items), and job performance (15 items). Data were analyzed using SPSS20 and descriptive statistics and artificial neural networks.
 Results: Among demographic characteristics, variables of marital status (% 16.7) and gender (% 1.5), among aspects of organizational knowledge, two dimensions of rewards (% 64.6) and leadership (% 4.3) and among aspects of Five-personality traits, accountability (% 100) and flexibility (% 11.3) had the highest and lowest importance coefficient respectively.
Conclusion: rewarding and accountability can improve nurses' job performance.
Therefore, hospital managers can help to improve their nursing performance by using appropriate rewarding mechanisms, reinforcing staff accountability and employing responsible personnel.