Clinical Microbiology is expanding with new discoveries in every of health and medicine. Diagnostic Microbiology subject one must be competent and look and think clearly to the subject. Once the clarity about the subject appears in the mind, it will be very easy to cope up with different types of every aspect of clinical Microbiology. Clinical Microbiology is a branch of medical science concerned with the prevention, diagnosis and treatment of infectious diseases. Moreover, this field of science is concerned about various clinical applications of microbes for the improvement of health. There are four kinds of microorganisms that cause infectious disease: bacteria, fungi, parasites and viruses. Epidemiology, the study of the patterns, causes, and effects of health and disease conditions in populations, is an important part of medical microbiology, although the clinical aspect of the field primarily focuses on the presence and growth of microbial infections in individuals, their effects on the human body, and the methods of treating those infections. Clinical Microbiology was written with the view to make microbiology ‘come alive’. While incorporating the essential material necessary for understanding the diagnostic techniques used, it provides comprehensive coverage of the practical aspects of the subject.