Most biomedical librarians are frequent users of the major online services provided by the National Library of Medicine (NLM), part of the National Institutes of Health in Bethesda, Maryland. These services include MEDLINE/PubMed, MedlinePlus, http://www.ClinicalTrials.gov, PubMed Central, document delivery, and other key biomedical resources. This article highlights less well-known services from reference, to historical information, to training and other services which librarians may not be aware the NLM offers to them. NLM encourages librarians to consider that NLM's unique and unsurpassed collection can help when local resources may be too limited to serve the needs of their patrons.