The microbial pathogenesis is the study of the biological mechanisms of the microbes that lead to the disease condition. Microbial pathogenesis deals with the mechanism through which the microbes can cause infectious disease and the development of the disease into acute or chronic illness. The pathogenic study of the disease condition allows the microbiologist to understand the underlying cause of the disease and identify the microbes responsible for the disease. This may also assist in controlling epidemics or preventing the outburst of the disease. The molecular and cellular mechanisms of infectious disease and its host-pathogen interaction and immunological response of various infectious agents are the key areas for a microbial pathologist.