The paper analyses the evolution and the contents of the ILO contributions to social justice during a century of its life: from the first Constitution of 1919, to the Declaration of Philadel-phia o 1944, to the Conference of 1998 which sanctioned the core labor rights, until the De-cent Work Agenda of 1999. The Author discusses the difficulties of applying universal labor standards to countries at different stages of development and the developing countries’ re-sistance to applying labor standards in international trade (which lasted until the declaration of 2008 on social justice for a fair globalization). Other parts of the paper concern the following issues: the new approach of the Decent Work Agenda and its implications for labor law; the proposals of the ILO for formalizing the informal work; the contribution of the ILO to the so-cial regulation of international trade, in particular through social clauses. In this respect, the Author indicates the reasons for the weak effectiveness of these clauses and the possible ways to reinforce them.
Keywords: Core labor rights; Decent Work; Social clauses; Informal work.