A hospitalwide computer system that combines protocol-specific information on investigational drugs with order entry is described. A large university teaching hospital had in place a computerized clinical information system. Among other uses, physicians used the system for direct entry of total parenteral nutrient solution orders and associated laboratory tests; labels are produced automatically. Personnel from the pharmacy and information services departments met to discuss how to apply the computer system to investigational drug information. The application they designed has three components: protocol information, order entry, and patient monitoring. Protocol information, including all the standard drug data plus regulatory and investigator information, is displayed as a report on the user's terminal. The order-entry pathway allows the research pharmacist to predesign medication labels that are specific to each study and include all required information. This saves time, ensures accurate labeling, and provides a means for generating patient charges. The patient-monitoring component provides information to the research pharmacist in a daily report to assist in locating subject patients and to monitor compliance with protocols. The system has improved the access of health-care professionals to investigational drug information and decreased the time pharmacists spend dispensing these agents. The system has been well received, although up to three weeks is needed to bring the information online. A hospitalwide information system is effective in disseminating information on investigational drugs and facilitating order entry.