The department is responsible for the following:

1. Preparation and maintenance of appropriate selection and acquisition policy for the National Library of Nigeria
2. Centralized acquisition of materials through purchase, gifts and exchange
3. Identify possible sources of books and other gifts for the national Library of Nigeria
4. Stock editing and identification of gaps
5. Cataloguing, classification and processing of non-Nigerian materials for state branches
6. Acquisition and processing of non book materials
7. Distribution of book gifts from foreign agencies such as Book aid International and USIS to schools, Public and academic libraries throughout the federation
8. Soliciting for book aid from Overseas on behalf of the national library of Nigeria
9. Partner with national and international agencies in the exchange of their intellectual works

The Department comprises of four Divisions namely:

1. Selection and acquisition
2. Cataloguing and Classification
3. Gifts and Exchanges
4. Preservation and Conservation