In this paper, the author analyzes the social security benefits for nonstandard workers, and investigates their potential discriminatory aspects. The data about social protection of non-standard workers are inserted in an analytic scheme, and examined under three perspectives: the guaranteed subjects, the eligibility, and the amount of benefits. The systems of "portability" of social security accounts are also evaluated, in order to reconstruct a unitary frame of social security protection. At the end, the author analyses some measures intended to decrease labour costs in connection with particular labour contracts. The multiplicity of problems related to fragmentation of social security protection of non-standard workers underlines the necessity to deeply rethink present welfare systems.