The article investigates the reasons behind the scant use of the instrument of collective gender discrimination, especially when compared to that of collective discrimination based on personal convictions, race, ethnic origin. It is suggested the need to strengthen the position of the equality bodies and to provide unions with the legal standing in courts. Unions are showing a growing interest in gender equality, despite the historical tradition. In addition, the article examines the burden of proof’s regime that, in the case of collective gender discrimination, could be improved by emphasising the collective dimension and the specificity of the gender factor with respect to other risk factors.