A system for matching a pair of patient records as belonging to the same individual or patient is disclosed. A set of matching rules (4) represents persistent characteristics of clinical properties of patients. A clinical property extractor (5) is used for extracting at least one first clinical property from clinical information contained in the first patient record (1) and at least one second clinical property from clinical information contained in the second patient record (2). A match detector (3) is used for detecting whether the first patient record (1) and the second patient record (2) relate to the same patient, based on the first clinical property, the second clinical property, and the set of matching rules 4. A demographic property extractor (6) is used for extracting demographic data.