The Heritage Library Division traces its roots back to 1994 with the integration of the West Indian Reference Library of the Central Library of Trinidad and Tobago and the Trinidad Public Library. Now housed on the 2nd Floor of the National Library Building, it serves as a premier research centre for the nation's history and contributions to knowledge and literature.

The Heritage Library Division, as outlined in the NALIS ACT No.18 of 1998, plays a pivotal role in Trinidad and Tobago's cultural, educational, and social development. It serves as a comprehensive repository of materials pertaining to the nation and the Caribbean, acting as a legal depository for publications and a resource for government materials. Additionally, it preserves, promotes, and exploits national heritage information.

The Heritage Library Division curates a diverse range of materials, including Trinidad and Tobago imprints, works by nationals, Caribbean literature, and oral histories. These materials are available in various formats such as books, periodicals, multimedia, and rare collections.

In the Heritage Library Division context, special collections are collections containing rare books, manuscripts, photographs, papers, audio and video recording or any item of unique value, that are important to the development of TT society.

The HLD has custody of approx. 105 special collections, and the amount is constantly growing. Some of the more notable collections include the Learie Constantine Collection, which details his life as a cricketer, politician, barrister and the first Black British Peer; the Masonic Lodge Collection which houses publications produced by various Lodges, the Wayne Berkely Collection of mas costume designs, the Julian Kenny Collection of Trinidad and Tobago flora and fauna.

As part of its oral history and genealogy activities, the HLD actively conducts oral history interviews, and collects funeral programs. These undertakings allow the Division to build its contemporary collections of unique historical sources that will impact future genealogical research.

The Heritage Library Division offers extensive services to the public, including research assistance, guidance in bibliographic tools usage, and photocopying/scanning services. Special provisions are made for the visually impaired, ensuring access to heritage materials through assistive technology and Braille resources.

The Heritage Library Division partners with stakeholders to host exhibitions and workshops, provide short-term loans of in-house curated displays, offer advice on the conservation and preservation of their collections, as well as advice on resources of national development

Through various programs, exhibitions, and literary events, the Heritage Library Division engages with the community, fostering a deeper understanding and appreciation of Trinidad and Tobago's rich cultural heritage. Conferences and publications further contribute to knowledge dissemination.

A notable aspect of the Heritage Library Division's efforts is its focus on preservation. The Preservation and Conservation Laboratory, which was officially commissioned in 2013, is responsible for ensuring the overall longevity of valuable materials housed within NALIS. Through this activity, the Heritage Library Division helps NALIS fulfil its role as the International Federation of Library Associations, Preservation and Conservation (IFLA-PAC) Regional Centre for the English-speaking Caribbean. The PAC Laboratory continues to serve the preservation and conservation needs of libraries, archives and other documentary heritage institutions through fumigation/freeze-drying, conservation treatments, bindery services, disaster recovery, technical consultations and preservation training.

This overview encapsulates the vital role and multifaceted offerings of the Heritage Library Division, enriching the cultural and intellectual landscape of Trinidad and Tobago.