National Library of Pakistan is a legal depository for all published literary heritage of Pakistan . It serves as top most knowledge resource centre of the nation as well as fountain head of Library developments in the country. The library strives to develop significant collection of human knowledge, comprehensive collection of national literary heritage and deliver excellent Library services for promotion of knowledge based society in Pakistan . The Library is responsible for National bibliographic control and preserves the literary heritage of the country for the use of present as well as future generations. A vast collection of publications about Pakistan, its culture, people and books authored by Pakistanis living abroad forms a major portion of National Library of Pakistan's main collection. A significant part of collection consists on manuscripts and rare books. National Library of Pakistan is an active member of many library communities in the world such as PLA, IFLA, CDNL and CDNLAO.

National Library of Pakistan serves as depository of some international organizations like Asian development bank, International labor organization, and US department of Publications etc. The Library is National ISBN Agency for Pakistani Publications