Personality variables have been widely used to predict job performance. However, according to an interactionist perspective, behaviour is affected by both situation and performance. So we expect personality performance relationship to be moderated by situational factors. In this study, we take core self-evaluation (CSE) as a measure of personality which affects the job performance. The CSE–performance relationship is expected to be moderated by situational factors, conceptualized using situational strength at work (SSW). Furthermore, this interaction of CSE, SSW and performance is expected to be different for age, gender, sector, education and business function (background variables). We undertook a field-based survey (N = 868) from different companies majorly from three sectors (manufacturing, finance and infrastructure) and functions (business development, operations and support). The results revealed that the CSE–performance relationship was moderated by situational factors. This moderation is dependent on the background variables. Theoretical and practical implications of the findings are discussed, and the future course of research is suggested.