The COVID-19 pandemic highlighted the importance of environmental cleaning and disinfection, as many studies suggest a link between the spread of infection and the cleanliness of the environment. There is an increased awareness of the relationship between effective environmental hygiene programs and infection prevention, patient harm reduction, and HCP safety. These programs also help institutions combat antimicrobial resistance by preventing infections and reducing the need for antimicrobials. EVS focuses on proper cleaning and disinfection of healthcare environmental surfaces to ensure a safe patient environment. They also facilitate the perception of a “clean facility” (e.g., shiny floors, odor control), which is a priority for both patients and HCP. The IP must understand the importance of the EVS department in patient safety and infection prevention. To meet this challenge, IPs should collaborate with EVS leadership and frontline staff through proper communication, audits, and education. Additionally, they should ensure that workflow practices and policies are consistent with regulatory requirements and up-to-date, evidenced-based practices. This chapter is divided into four major points: 1) the structure and challenges of EVS; 2) the importance of environmental cleaning and disinfection in preventing healthcare-associated infections (HAIs); 3) the principles and types of disinfectants, including newer agents and technologies; and 4) the connection between IPs and the EVS department.