The Pittsburgh Reference Library Alliance (RLA) represents a successful response by hospital laboratories to the new realities of medical economics and practice. By using informatics technology to integrate the laboratory resources of community hospitals and academic medical centers across western Pennsylvania, the RLA has created a large virtual laboratory that can compete for price with large national referral laboratories. More significantly, the combination of medical expertise, the ties to academic and community centers, and the regional medical database of the RLAs allows laboratory medicine to be practiced in a new proactive way. This should provide better and more cost-effective patient care. The success of the RLA is a model for regional cooperation in pathology and potentially in other medical specialties and demonstrates the importance of informatics in the future of medical practice.