Aims: To analyse the predictive validity of 18 psychosocial work environment scales from the Copenhagen Psychosocial Questionnaire version II (COPSOQ II) with regard to risk of sickness absence. Methods: The study population consisted of 3188 wage earners (52% women) from a representative sample of Danish residents. Participants received the long version of the COPSOQ II in autumn and winter [2004][2005], including 18 psychosocial work environment scales from the domains ''Demands at work'', ''Work organization and job contents'', and ''Interpersonal relations and leadership''. The study endpoint was register-based sickness absence of 3 weeks or more in the 1-year period following completion of the COPSOQ II. Associations between COPSOQ scales at baseline and sickness absence at follow-up were analysed with Cox proportional hazards models, adjusted for age, gender, prevalence of a health problem at baseline, and occupational grade. Results: Sickness absence during follow-up was predicted by a one standard deviation increase on the scales of cognitive demands (hazard ratio (HR) 1.17, 95% confidence interval (CI) 1.00-1.37), emotional demands (HR 1.28, 95% CI 1.10-1.50), and role conflicts (HR 1.32, 95% CI 1.15-1.52). After applying adjustment for multiple testing, the effect of emotional demands and of role conflict remained statistically significant, but not the effect of cognitive demands. Conclusions: Selected psychosocial work environment factors from the COPSOQ predict register-based sickness absence in the Danish workforce.