Non-marital cohabitation, as a community of life of two people connected only by the feeling of love and desire for living together, without form and registration, is an institution as old as marriage. Throughout history, attitude of the legislator has been changing from forbidding to ignoring it. In our society there is a negative attitude towards non-marital cohabitations, which is the result of patriarchal ideas and customs. However, the Constitution of the Republic of Serbia and the Family Law equate marriage and non-marital cohabitation. In this paper, the author will try to determine to what extent in terms of effects the marital and non-marital cohabitation are equal, or to what extent the rights of non-marital partners are recognized. The subject of analysis are primarily the Constitution and Family law, but also many other regulations governing the issues relating to the rights and obligations of non-marital cohabitation partners. In fact, although Family law equalizes marriage and non-marital cohabitation, they are not equal either de facto or de jure. The author will try to point out the deficiencies in the legal regulations, the practical problems and suggest possible and better solutions.