A study was done during 1991–1992 to determine the perceived impact of electronic mail (E-mail) relative to other forms of communication in health sciences institutions. E-mail subscribers at two major health sciences institutions were sent 2919 surveys, and 823 (28%) completed survey instruments were returned. A significant positive impact of E-mail was found relative to other forms of communication (e.g., paper, phone) with regard to E-mail messaging, response rates, influence, value, formality, perceptions, errors in communication, cost-effectiveness, communication style, and other factors. Areas where no differences were found between communication mechanisms were also revealing. Technical problems, maintenance, and confidentiality of E-mail messaging were not found to be significant problems. Trends, value, and impact of E-mail use in health sciences institutions are also discussed.