Architectural Documents - over 400 drawings of local structures, including some historic documentation (HABS) and restoration projects. Architects represented include Atlee B. Ayers; Robert M. Ayers; Ralph Cameron; Bartlett Cocke; Ford, Powell, & Carson; Alfred Giles & Guindon; J. Reily Gordon; Robert H.H. Hugman, and George Willis.

Archives and Special Collections - the archives documents the evolving history of the San Antonio Conservative Society. It includes the past presidents' scrapbooks, 1924 - 1999; NIOSA scrapbooks, 1944 - 1986; newsletters, 1955 - present; yearbooks, 1924 - present; and 16.5 linear feet of documents in vertical file form without formal finding aids. The Special Collections consist of rare books and manuscripts documenting the history of San Antonio or that of the San Antonio Conservation Society.

Books and Periodicals - over 4800 volumes focusing on architectural history, historic preservation and urban planning, architectural restoration techniques, and San Antonio and general Texas history. The collection also includes San Antonio City Directories, 1877 - 1996, although not every year is covered.

Clippings Files - over 98 linear feet of articles, brochures, photocopied documents, and research notes covering a variety of people, places, and things related to San Antonio.

Historical Photographs and Postcards - 7700 photographs, in addition to the Ernst Raba Collection of early San Antonio views, the Dorothy Matthies Postcard Collection (early San Antonio, Galveston, and Houston), and the Graham-Ford Collection of stereographs.

Maps - approximately 374 maps depicting Texas, Bexar County, and San Antonio, c. 1687 to 1996. San Antonio maps include Augustus Koch's nineteenth century Bird's Eye Views and a complete set of 1952 Sanborn Fire Insurance Maps.

Oral History Maps and Transcripts -  over one hundred tape-recorded interviews cover a range to topics from local and Society history to historic preservation issues and strategies. Unbound transcripts are available for the majority of recordings. Appointments to listen to recorded interviews must be made in advance.