The Laboratory Information System (LIS) was designed as a "turn-key" system. The main functions are operated interactively on a mini-computer which gives the laboratory complete control over daily processing. Collection of results from automated analyzers is accomplished via a micro-computer/micro-processor network. Links are provided with a central main frame computer for immediate patient identification and historical data processing. LIS is designed to manage all the operations involved in laboratory activities. The system has 14 major functions: registration of test requests, production of specimen collection sheets and identification labels, confirmation of specimen collection, production of aliquot labels, workload inquiry, production of worksheets, manual entry of test results, automated entry of test results, results inquiry, preliminary report, final report, daily activities reports, statistical reports, billing. System security is provided along three directions: data entry validation, system access control, and memory protection. The main advantages of LIS are: reduced clerical work, better evaluation of workload, faster communication, improvement of information given to the clinician: adapted reference values, interpretation, comments, improved retrieval operations, faster billing.