The Generalized Record Linkage System is a probabilistic record linkage system designed for use by a wide range of statistical applications. It is part of a toolbox of generalized systems developed at Statistics Canada in response to business and health needs. This article gives an overview of the record linkage system and its application in the health area. The system is used to improve data quality and coverage, for long term medical followup of cohorts, for creating patient-oriented rather than event-oriented data, for building new data sources, and for a range of other statistical purposes. Described are the three main stages in carrying out the linkage, namely 1) the searching stage; 2) the decision stage; and 3) the grouping stage. Outlined are the essential criteria for the evaluation of such software.