We describe a clinical laboratory information system for the RAST laboratory based on personal computers. In developing this system, we paid special attention to easy handling which does not require any computer experience on the user's side. Data storage and retrieval are managed by a relational database system with fast data access. Aside from the usual functions of a laboratory information system, the laboratory work is facilitated by a clear distribution of samples, the possible on-line connection to various analyzers, as well as the provision of cumulative results and a fast access to archive data.