Tuberculosis is a contagious and destructive disease that has plagued humans and their domesticated animals for at least 6000 years (Morse, Brothwell, and Ucko 1964), and continues to be a serious disease worldwide. Like most infectious diseases, the virulence of tuberculosis constantly fluctuates as changes occur in the host, the pathogen, and the environment. For example, in the United States, cases of tuberculosis are on an increase after a century of decline. A new population of homeless, intravenous drug users, and AIDS victims has provided an environment favorable for the comeback of tuberculosis in the United States. The spread of tuberculosis is tied very closely to human cultural practices and human biology. Living conditions, nutritional status, occupation, health, age, sex, group affiliation, and many other factors play a role in the susceptibility of individuals to tuberculosis. The possibilities for research on tuberculosis are endless. Because of the steady decrease in mortality until the last decade, researchers have almost ignored tuberculosis (Weiss 1992). This paper provides a basic understanding of the disease process involved in tuberculosis and addresses some of the major research currently being dealt with by researchers. It is not the purpose of this paper to exhaust any one of these topics but to provide an overview of some of the more important ones.