For the past year we have been using a relational database as part of an automated data collection system for cryoEM. The database is vital for keeping track of the very large number of images collected and analyzed by the automated system and essential for quantitatively evaluating the utility of methods and algorithms used in the data collection. The database can be accessed using a variety of tools including specially developed Web-based interfaces that enable a user to annotate and categorize images using a Web-based form. (C) 2002 Elsevier Science (USA). All rights reserved.