The library has over the years built a robust collection of over 1, 50000 books, 40,000 bound volumes, 335 current subscription to journals and newspapers. Besides printed books and journals, its collection contains all forms of documents such as CD-ROMs, On line databases, manuscripts, rare books microfilm and reports etc.
The collections held at IIAS Library have been recognized for their outstanding national and international importance. The collection development of library began with an effort of Shri B. S. Kesavan, then Director of the Indian National Scientific Documentation Centre, New Delhi. As Library Advisor to the Institute, he was able to place ten thousand volumes on the shelves on the day of the Institute's inauguration on 20th October, 1965. The library's collection was further enriched by the acquisition of private collections of eminent scholars. Organizations like the British Council, the Asia Foundation, and League of Arab Nations have made generous gifts of hundreds of rare pamphlets and books. Later, the library obtained rare Sanskrit, Arabic and Persian texts and manuscripts containing miniature paintings.
The Library holds major collections of books in History, Comparative Religion, Psychology, Philosophy, Sociology, Anthropology, Literature, Economics, and Public Administration. While building up its collection, there has always been a conscious endeavor to maintain a balanced growth of collections covering both the broad subject areas of research in Social Sciences and Humanities as well as highly advanced areas of interdisciplinary research like science of consciousness, working of mind, various facets of ancient Indian history, Culture and Civilization, Postmodernism theoretical and cultural studies pertaining to philosophy, religion, political science and sociology gender and environmental studies socio-economic planning and development, Gandhian Studies and the like.
Besides the main section of the Library which consists of English language publications, the Library has developed the following separate sections:

1. 1. Hindi language publications
   2. Sanskrit texts
   3. Publications in modern Indian Languages other then
   4. Professor R.C. Majumdar Collection
   5. Professor H.C. Ray Chaudhuri Collection
   6. Professor Hari Shankar Srivastava Collection
   7. Special collection of Classics consisting of Publications like Tibetan Tripitaka (168 volumes) and the publications brought out under loeb classical library series of Harvard Univ. Press., Sacred books of the East, Great Books of the Western World etc.
   8. Arabic, Persian and Urdu manuscripts as well as printed publications.