The INternational VErapamil SR/trandolapril STudy (INVEST) is the first long-term, large-scale clinical trial being conducted primarily using Web-based technology. The Web is a powerful tool for enhancing clinical trial management because of its ability to centralize all study information and coordinate multiple trial processes in real time at lower cost. The result is improved efficiency, accuracy, and safety in clinical trials conduct. In Web-based clinical trials, sites are able to focus primarily on medicine and science, rather than on trial administration. Site training, study documentation, subject recruitment, randomization, medication dispensing, and management procedures are simplified by using Web-based software to enhance processes. This paper summarizes the advantages achieved for INVEST investigators, sponsor representatives, monitors, and subjects resulting from the centralization and coordination of multiple tasks through Web-based technology.