In a broad sense, LILACS covers all Health Sciences addressing the human health: Medicine, Public Health, Dentistry, Nursing, Veterinary Medicine, Sanitary Engineering, Pharmacy and Chemistry, Biology, Nutrition, Psychology, Ecology and Environment, etc.

It should be borne in mind that the system is intended primarily for those in the health profession, from the expert in the areas of Medicine, Dentistry or Nursing, the Public Health professional, the rural physician, the health care personnel to the health administrators linked to the Health Ministries and State Secretariats.

The documentary language that covers LILACS subject matters is generally included in DeCS – Descriptors in Health Sciences, a controlled vocabulary that helps the documentalist in the analysis of a document to be included in the database, and contributing also to its future retrieval.

A document is qualified for inclusion in the LILACS database whenever you can describe its content using one or more DeCS descriptors. DeCS is the translation into the Portuguese and Spanish of the Medical Subject Headings (MeSH), produced by the U.S. National Library of Medicine. Expansions in Public Health (SP), Homeopathy (HP), Science and Health (SH) and Health Surveillance (VS) were made in addition to the original document (MeSH). The Annex I presents DeCS main Categories.

The expansion in Public Health (SP) fulfils the need to process data generated by PAHO Special Centers and Programs. To the SP Category were added subjects such as: Administration and Health Planning, Provision of Health Services, Epidemiology and Biostatistics, Demography, Environmental Health, Nutrition, etc.

The subject matters covered by LILACS are not submitted to strict limits and common sense is the best judgment. Documents regarding human health can also be considered in the following areas: Sanitary Engineering, Pharmacy and Chemistry, Veterinary Medicine, Biology.