Purpose Based on the self-evaluation maintenance model and social comparison theory, the purpose of this study is to test a novel model to explore the influence of competitive psychological climate on knowledge withholding of employees with the mediating role of envy. This study also investigated when the effect of climate on envy is more pronounced by assessing the role of a narcissistic personality. Design/methodology/approach The authors collected time-lagged data from 376 employees working in UAE national banks to test the model. Findings The findings of this study showed that a competitive psychological climate indirectly affects knowledge withholding behaviour because such a climate enhances the emotional response of employee envy. In a competitive climate, upward social comparisons are likely to be heightened, resulting in employee envy and knowledge withholding because knowledge is used as leverage to gain self-control and self-worth in the organisation. This effect of such a climate on employee envy was found to be stronger when employees have a narcissistic personality. Originality/value The findings offer practical insights to managers and practitioners on the importance of managing the competitive climate cautiously to address the likelihood of knowledge withholding behaviour among employees at work.