The Telomerase Database is a Web based tool for the study of structure, function, and evolution of the telomerase ribonucleoprotein. The objective of this database is to serve the research community by providing a comprehensive compilation of information known about the telomerase enzyme and its substrate, telomeres. The collection of information includes sequences, alignments, secondary and tertiary structures, mutations known to cause human telomerase deficiency diseases, and current telomerase researchers.