The concept of national human rights institutions (NHRIs) as known today originated under the auspices of the United Nations. Although national human rights institutions in the contemporary context have been the subject of a growing body of literature, the evolutionary path of the very idea of their creation has remained largely unexplored. The aim of this paper is to fill this literature gap by analysing key United Nations documents from the end of World War II to the adoption of the 1978 Geneva Guidelines. The paper reveals how the very concept of national human rights institutions had evolved over time, how it had been understood, which functions had been tied to these institutions, and which organizational forms had been taken as models. The paper explores the changes in the attitudes of UN Member States in relation to a given issue and provides a better understanding of the context in which this idea developed. In this regard, the paper also offers new insights into how the process of negotiating the core UN human rights conventions has influenced the evolution of the idea of creating national human rights institutions, a factor that has been rarely considered.