A system is described which incorporates the use of a diagnostic and treatment advice expert system into the routine information-handling functions of a surgical breast clinic. The main focus of the system is on identification and management of non-malignant breast disease. The advisor is linked with a clinical database which is used to hold summary case notes, and from which reports forming the basis for audit of case-mix and resource utilization can be produced. The system uses backward chaining of extended production rules and a relational database, and runs on a desktop microcomputer.