The paper addresses the role of the International Labour Organization (ILO) in the consideration of cases and in the interpretation of international human rights instruments by the Committee on Economic, Social and Cultural Rights and the European Court of Human Rights. As labour rights form part of internationally recognized human rights the author attempts to evaluate the penetration of ILO standards and legal reasoning into the adjudication of human rights cases and interpretation of human rights instruments by other international bodies. The analysis of the jurisprudence of the CESCR and the ECtHR demonstrates that the ILO standards and the legal reasoning are always referred to in the cases related to labour rights and serve as a source of “substantial filling” of both the International Covenant on Economic, Social and Cultural Rights and the European Convention on Human Rights.