Microbiological investigations are important in the diagnosis, treatment, and surveillance of infectious diseases and policies regarding the selection and use of antimicrobial drugs. It is, therefore, essential that test reports are relevant, reliable, timely, and interpreted correctly. High cost of culture media and reagents, lack of rational approach to the selection and use of microbiological investigations, and a shortage of trained technical staff and clinical microbiologists are important factors in preventing the establishment of essential microbiology services in developing countries. This book encompasses all the aspects of quality management in a Microbiology laboratory such as quality assurance & quality control , various factors influencing quality. An attempt has been made to discus various aspects of Audit , Benefits of Acceditation , to avoid confussion between validation & verification & to highlight all the facets of ISO 15189:2007 & steps of Acccreditation to our readers in a palatable form.