Core self-evaluations (CSE), a personality construct underlying self-esteem, locus of control, generalized self-efficacy, and neuroticism, has previously been found to relate strongly to job satisfaction. While previous research has shown relationships between personality traits and various adverse psychosocial job outcomes, no published studies have looked at the relationship between CSE and job stress. A study was conducted to test the effects of job demands, job control, and social support, as hypothesized in the job demand control support (JDCS) model, and the effect of CSE on job stress. Two hundred and twelve employees from 12 work places in southern Norway filled in a questionnaire consisting measures of job demands, job control, social support, CSE, and job stress. Initially, the results from hierarchical multiple regression analysis showed significant main effects of demands and control on job stress. However, when social support was included in the analysis, control was no longer significant. In addition, ANOVA showed that the two-way job demands x job control interaction effect, and the three way job demands x job control x social support interaction effect, as predicted by the JDCS model, were nonsignificant. The results showed a strong positive main effect of CSE on perceived job stress, and that CSE accounted for a large proportion of the variance in job stress. This is in accordance with studies that have shown relationships between other personality measures and job stress. The present study confirms the relevance of CSE for further research on links between personality and job stress.