Introduction: Cooling towers were originally believed to be the main source of Legionella bacteria, as the US Centers for Disease Control (CDC) found that a cooling tower near a hospital with cases of Legionnaires' disease was contaminated with the bacteria. However, since this discovery, there have been few reported cases of hospital-acquired Legionnaires' disease linked to cooling towers. This review aimed to explore the interventions to control infections transmitted through drinking water in hospitals. Methods: The review searched for published peer-reviewed literature in English from 2000 to 2022 in the Medline Embase, Aqualine, and National Guidelines Clearing House databases. The review focused on critical care units, such as neonatal, pediatric, adult intensive care, burns, organ transplant, oncology, hematology, cystic fibrosis, and renal units. The review included experimental and epidemiological study designs such as non-clinical experiments, randomized controlled trials, non- randomized controlled trials, quasi-experimental studies, before-and-after studies, prospective and retrospective cohort studies, case-control studies, and analytical cross-sectional studies. Results: Out of 196 potentially relevant studies identified in the search, 21 were assessed for this review. Of these, 11 provided plausible evidence, while the remaining 10 provided descriptive evidence of low plausibility. The majority of the studies focused on understanding the occurrence of Pseudomonas aeruginosa outbreaks in critical care units. Most of these studies were retrospective analyses of outbreaks or short-term prospective follow-up studies in intensive care or hematology-oncology units. Only two of the studies included comparison groups. Conclusions: the research suggests that the water and plumbing systems in healthcare units can be a source of Pseudomonas aeruginosa and legionella, a bacteria that can cause colonization or infection in patients. This is especially likely if the bacteria is able to form biofilms, which may be facilitated by certain types of plumbing materials and locations.