It has been entrusted by law as the national institution responsible for collecting, bibliographically recording, preserving and making available the nation's collective memory, and also provides information on practically all branches of knowledge, and functions as a center of coordination, planning and stimulation of the country's library system.

The main role of the National Library of Mauritius is to build a comprehensive collection of our national heritage by collecting, receiving and preserving all publications and productions, printed and produced in Mauritius for present and future generations.

The main source of acquisition is by means of the legal deposit system as per the National Library Act 1996 which stipulates that every printer in Mauritius is required to deposit, free of charge, with the Director of the National Library six copies of each publication, be it a book, periodical, report, newspaper or any other printed document.

The National Library is also responsible to build a collection of foreign reference materials on different subjects of interest for the benefit of the Mauritian public at large.

The National Library's Mauritius collection consists of materials in various formats such as: written or graphic records, typescripts, books, newspapers, periodicals, music scores, photographs, maps, drawings, and non-print materials such as films, filmstrips, audiovisual items including tapes, discs and reproductions relating to any subject and produced in Mauritius or relating to Mauritius and produced overseas.