Investigate the impact of psychological job demands and resources on chronic fatigue.Nurse fatigue is a serious problem with negative consequences on patient safety and nurse wellbeing. Excessive job demands can exacerbate nurse fatigue, which may limit the ability of nurses to engage in professional practice.This two-wave study was carried out with a self-report questionnaire administered to nurses in eastern Canada (n=154). Cross-lagged analysis using structural equation modelling was conducted to examine the interactions between psychological job demands, resources and chronic fatigue over time.Results showed that psychological job demands predicted chronic fatigue a year later. Nonetheless, job resources (decision latitude, support support) did not buffer the relationship between psychological job demands and chronic fatigue one year later.Psychological demands have a long-term effect on chronic fatigue, thus interventions to mitigate fatigue are needed.Nurse managers should be aware of the cumulative effects of chronic fatigue and implement strategies to create a better balance between job demands and resources in the workplace. This article is protected by copyright. All rights reserved.