Pennsylvania Spatial Data Access (PASDA--http://www.pasda.psu.edu) is a World Wide Web-based NSDI spatial data clearinghouse for the Commonwealth of Pennsylvania. PASDA was developed by Pennsylvania State University with funding from the Pennsylvania Department of Environmental Protection to provide public access to data and metadata related to Pennsylvania. The primary functions on the PASDA system include an FTP site for downloading data sets, an interactive mapping component for users without a GIS or GIS knowledge, and an extensive metadata catalog. Metadata is the heart of the PASDA system allowing users to locate data using a number of search functions. The PASDA metadata team has initiated an aggressive effort to identify, document, and when possible acquire data throughout the State for incorporation into the site. This effort highlighted issues related to data sharing including cost recovery, data redundancy, and the need for metadata training, especially among local governments. This presentation will include a discussion of PASDA, its functions, components, development, and related projects, and will focus on the key role of metadata in the success of the system.