More than 46 million surgical procedures are performed each year in the United States, in addition to many more millions of invasive medical procedures. Reusable medical instruments and devices are utilized in all of these procedures, each requiring reprocessing in order to be safely reused. Appropriate cleaning is a critical step in the multi-step reprocessing of reusable instruments and medical devices. The importance of this step is often overlooked; however, if a device is not clean, it cannot be properly disinfected or sterilized. Thus, improper cleaning poses a considerable health risk. In this program, the risks associated with the improper or incomplete cleaning of medical instruments and devices are identified. Additionally, the components of cleaning solutions and factors that impact their effective use will be addressed.