After the strict interpretation of the affirmative actions' boundaries of legitimacy held in the much criticised Kalanke decision, in the recent case Marschall the European Court of Justice softens its rigid stance and recognizes that national rules giving priority to women, between equally qualified applicants of different sex, for the access to job positions in which women are under-represented, are covered by art. 2.4 of the equal treatment directive, on condition that such priority isn't absolute but only a trend. The essay analyses the legal basis and the meaning of this case law. Firstly, the author explains how counteracting female under-representation in certain employee positions has to be considered a legitimate aim of the affirmative actions provided by EC law, denouncing in any case the illegitimacy of those measures directed to the guarantee of equal - and not proportionate-representation of male and female employees. As it is underlined afterwards, not every kind of preferential treatment is nevertheless allowed in the pursuit of that objective: the requisites that quota systems must possess to comply with the fundamental EC law principle of proportionality are therefore illustrated.