The SIECUS Information Service and Mary S. Calderone Library is one of only four sexuality libraries in the United States and is the only one open to the public. This article dcscribes the history and founding of the library; staffing; the collection; the users; the services; and computerization plans. Also detailed are the library's contribution to SIECUS' bimonthly periodical which include seven annotated bibliographies of print and audiovisual resources available for purchase; convening an Audio-visual Review Panel and writing their opinions into the audio-visual reviews; and evaluation and writing up of "Resources to Write For."