About 34 percent of medical scientists, except epidemiologists, were employed in colleges and universities. About 28 percent were employed in scientific research and development services firms; 12 percent were employed in pharmaceutical and medicine manufacturing; 9 percent were employed in hospitals; and most of the remainder were employed in private educational services and ambulatory health care services.
Among epidemiologists, 57 percent were employed in government; 12 percent were employed in hospitals; 11 percent were employed in colleges and universities; and 9 percent were employed in scientific research and development services.
Source: Bureau of Labor Statistics, U.S. Department of Labor, Occupational Outlook Handbook, 2008-09 Edition