According to World Health Organization, 70-80% of the world’s population depends on the herbal medicines for their primary health care. Regardless of extensive applications of herbal medicines, this fact cannot be denied that, the plant materials are exposed to various contaminants like toxic elements, pesticide residues, insects etc. But, the main contaminants chiefly responsible for the deterioration of the herbal products are the microbes. They exert a bad impact on the overall quality and shelf life of the herbal products. Thus, evaluation techniques for contamination should be pointed out at every manufacturing step to assess the microbial contamination level on crude drug.