To practice mammography diagnosis effectively, radiologists expect convenient access to well-organized and authoritative mammography related information, especially when there is case in question. The purpose of this study is to build infrastructural diagnosis support by incorporating various clinical information into a digital mammography case library, and allow user to search the library based on mammographic findings. The digital mammography case library has a three- tier architecture: (1) Back-end mammography databases integrate multimedia clinical information from various operational systems, including RIS and PACS. Cases are stored in a finding index database powered by an object-relational database with finding-coded reports, which are modeled around the ACR BI-RADS (American College of Radiology, Breast Imaging Report and Data System) standard. (2) The middle-end application controllers process application logic, such as user authorization, HTTP request handling, database connection and dynamic HTML page generation. (3) Web-based user interface is developed for authorized Intranet personnel to formulate query based on radiological finding (such as mass, calcification and architectural distortion), shape and assessment, using ACR BI-RADS specified lexicon. The case library so far has 103 cases selected from over 800 digital mammography studies carried out at the Mt. Zion hospital, UCSF, during an on-going digital telemammography project. We believe that an Intranet based digital mammography case library with mammographic finding search capability facilitates continuous medical education and online decision support, by providing exemplary study to compare with case in question.