Economical legitimacy presupposes realization and recognition of given economic institutions as necessary and having in public opinion the right to exist. This recognition serves as a basis for social trust, which, in turn, appears as an essential condition for their effective operation. Due to the conditions of the «catch-up» modernization those institutions were mostly shaped by the state, and the problem of social recognition is quite relevant for them. In general, legal basis for non-profits, support from political institutions and well grounded reasoning of their advantages in scientific discourse are a sign of successful legalization of non-profit organizations in the social and economic space of modern Russia. However, things are not as simple with their economic legitimacy. Conflicting results show mistrust for them in major part of population. The legitimacy factors of socially oriented non-profits are being analyzed in the article. Discrepancy between the structure of focus area of socially oriented non-profit organizations and social needs of the general public is pointed out, as well as high transaction costs. Economic legitimacy of socially oriented non-profits serves as an indicator of such organizations being ready to take upon themselves the social services provision. The legitimacy level today shows that a very small part of the non-profit sector of such services is ready for that mission.