Personality plays a major role in the way we interact with others in the workplace and how it affects organizational behaviour. We spend considerable number of hours with our colleagues and it’s their personalities that we interact with. The purpose of this study was to analyze personality trait and its effect on organization behaviour. The big five personality traits theory was used to guide the study and the ex-post-facto research design was employed. The target population comprised 100 individuals working in the education department in Nakuru County. A sample of 30 respondents was arrived at using simple random sampling. Qualitative content analysis focused on interpreting and understanding work done on personality traits and workplace behaviour was also carried out. Reliability of instruments was established through face validity as well as checking through content stability and accuracy using Pearson Correlation Coefficient of 0.70 that was deemed reliable. Validity was established by checking on closeness of the categories and conclusion of work done as well as through content and face validity. The study found out that there is a significant relationship between personality traits and organizational behaviour. Openness, conscientiousness, extroversion and agreeableness personalities have an easier time with workplace changes and are more adaptable as compared to neurotic subjects who perform worse, and have a tougher time managing emotions. Therefore, there is need to have a deeper understanding of personality traits in workplace to help coworkers and managers create trust, better relate to one another and cultivate a good working environment.