This paper analyses implications of the ruling made by EU Court of Justice in March 2011 in the case Test-Achats vs. the Council of Ministers. This ruling effectively forbid any differentiation of insurance premium depending on the sex of the insured person. Decision was supported by the statement that banning differentiation of insurance premium on basis of gender of the insured, as an element of the Gender Mainstreaming Policy element, may cause adverse effects on commercial insurance market. Most likely effects of this decision are: reduction of the quality of risk management process at assessment level, increase of the average insurance premium, reduction of the market product range, decreased demand for insurance products, impact on image of insurance companies, further inequalities between genders.