The Flow Cytometry and Imaging Shared Resource of the Massey Cancer Center was founded in 1976. Its instrumentation has been regularly upgraded through six generations of flow cytometers to the two instruments currently in use, a Coulter EPICS Elite-ESP and Coulter XL- MCL. The Elite is a multi-laser system with multi-parameter sorting capabilities, operated solely by the Laboratory Manager. This highly flexible but complex system can be configured for a wide range of custom applications. The XL is an automated, user-friendly system that can be operated by appropriately trained users of the shared resource facility. The facility also includes a Meridian Ultima confocal scanning microscope for fluorescence analysis and imaging of attached cell cultures or solid tissues. Since its beginning, this shared resource facility has served over 100 laboratories, mot of whom are affiliated with the Cancer Center. The Director, W.M Grogan, has established considerable expertise in a wide variety of flow cytometric methods and has published a monograph on this technology. The Resource provides a wide range of services from routine fluorescence analysis to interactive custom design of innovative analysis and sorting protocols, addressing the specific needs of individual investigators. Dr. Grogan closely follows the analyses performed by the shared resource facility, insuring quality control and advising facility users on alternative , often novel, approaches to experimental design and data analysis. To address increased demand for services and maximize instrument usage, the Resource has recently consolidated its facilities, instituted a user training program and proposes to hire an additional technician, expand working hours and upgrade its computers an data analysis software. This Shared Resource maintains a stable base of instrumentation, expertise and trained personnel that currently provides flow cytometry services and training for multiple users in 26 different research groups at VCU. It has had a major impact on research at VCU for almost 25 years.