It has long been recognized that medical and surgical devices may serve as vehicles for the transmission of infectious agents to a susceptible host. Our knowledge and experience involving microbial inactivation through disinfection or sterilization have become quite sophisticated. As a result, many of the infectious problems of the past are now well controlled. Modern hospitals are no longer places to be feared. Infectious complications associated with patient care are now the exception rather than the rule. These major advances in patient safety have been due, in large measures, to our ever-increasing knowledge and understanding of our microbial environment. We have learned how to control microorganisms through our understanding of what they are, where they are, how they are transmitted, and where their strengths and weaknesses lie. Disinfection makes handling instruments safe for further packaging and sterilization. Quality disinfectants are necessary to ensure that the reprocessed instruments are free from pathogens. The efficacy of a disinfection process depends on effective cleaning to remove all the organic matter, which would otherwise interfere with the activity of the disinfectant chemicals. All disinfectants are used at appropriate dilutions and it is mandatory that expiry dates are marked for in-use solutions. Other manual and automated methods are available for effective implementation of a washing-disinfecting procedure in the CSSD.