This study analyzes the relation between works councils and overtime hours in Germany. The estimated effects differ considerably in dependence of standard contracted working time. Furthermore, we find differences across the quantiles of the overtime hours distribution and these differences between quantiles also vary between employees of establishment with and without works councils. By considering contracted working time effects and comparing conditional quantiles we find in some quantiles that employees of establishments with a works council have a higher amount of overtime hours if an employee regularly works 35 hours per week. This effect diminishes with increasing quantiles of the distribution of overtime hours. If an employee of a codetermined establishment regularly works 40 hours per week, overtime hours are reduced. This reduction becomes larger if higher quantiles are analyzed.