A partnership of medical laboratories in Ontario, Canada has developed and made operational a centralized interactive database of cervical cytology (Pap) reports. This system automatically registers some 60,000 reports monthly, which are submitted electronically from geographically diverse sources. Patient histories are provided on-line to authorized pathologists to support ongoing diagnoses. A formalized coding system has been developed to represent elements of Pap reports in machine readable format, including diagnosis, clinical information about the patient, specimen adequacy, methods of specimen collection and follow-up recommendations. The system operates over a private network based on Internet standards. A review of operations, which commenced June 1, 1996, provides insights into applied EMR technology.