AIM: To investigate potential differences in sickness absence among public sector employees in Sweden and Denmark, and to what extent a difference was associated with age, gender, physical and psychosocial work environment exposures, lifestyle factors, self-rated health or work ability. METHODS: In 2000, two cross-sectional samples of 8562 public sector employees in Sweden and Denmark were surveyed. The study outcome, self-reported number of sick-leave days the year preceding interview, was dichotomized into 7 days or less, and more than 7 days. Chi square test was used to analyse distribution of dependent and independent variables in the two sub-cohorts. Stratified logistic regression analysis was performed to identify causes for absence within the two sub-cohorts, and logistic regression analysis was performed to study differences in sickness absence levels between the two sub-cohorts. RESULTS: More subjects from the Swedish study population reported more than 7 days of sickness absence. Factors associated with sickness absence were largely similar in the two countries. The difference in absence level between Sweden and Denmark was not associated with differences in age, gender, skill level, lifestyle, psychosocial or physical work environment, musculoskeletal symptoms or self-rated health, whereas work ability score decreased the difference in sickness absence level. CONCLUSION: The results could indicate an increased retention of employees with health problems in the Swedish labour market compared with the Danish labour market. A possible explanation for the differences in sickness absence ascertained in this study could be due to differences in the sickness insurance legislation.