Good practices in a microbiology laboratory consist of activities that depend on several principles: aseptic technique, control of media, control of test strains, operation and control of equipment, diligent recording and evaluation of data, and training of the laboratory staff in related competencies. Because of the inherent risk of variability in microbiology data, reliability and reproducibility are dependent on the use of accepted methods and adherence to good practices in the laboratory. This chapter does not cover the unique and specific laboratory activities for virology and mycoplasma recovery and detection.