United Nations Educational, Scientific and Cultural Organisation (UNESCO), documents Needham's role in the establishment of UNESCO and his Directorship of the Section of Natural Sciences. From an early date Needham kept material he believed would be of historical significance, particularly those papers relating to his three memoranda on the establishment of international science co-operation and the creation of UNESCO. The largest component is material relating to the Section of Natural Sciences 1946-1948. There are also papers from meetings of the UNESCO Executive, and papers relating to the project for a Scientific and Cultural History of Mankind. The section also includes papers of the British Committee for Co-operation with UNESCO in the Natural Sciences.