Objectives: To explore regional differences in the effects of the sick leave frequency determinants between two homogeneous groups of workers from two comparable socio-economic regions in the Netherlands, namely Utrecht and South Limburg. Materials and Methods: Data on sick leave frequency for 137 cleaning workers in the regions of Utrecht (mean sick leave frequency: 0.89 spells) and South Limburg (mean sick leave frequency: 1.66 spells) were obtained from a Dutch social fund, and the data regarding their job, and health-related and individual characteristics were elicited by an interview. Results: A statistical analysis of the sick leave frequency in the two regions showed little differences, except for the determinant 'perceived physical workload' which was associated with the sick leave frequency in South Limburg but not in Utrecht. Conclusion: A regional difference in the sick leave frequency was noted with respect to 'perceived physical workload' as the study parameter. This would indicate that the findings of our earlier studies performed in the nineties of the last century. are still relevant. In further research, the principles of the new certification system on sick leave frequency should also be considered, as the previous uniform statutory compensation system has been terminated.