The Pastormaster method consists of heating the water of hospital distribution systems at a specific point to a sufficient temperature for a minimum amount of time to eradicate legionella. The object of this study was to evaluate the effectiveness of the Pastormaster method for legionella disinfection in a hospital environment. A two-phase procedure was performed: hydraulic optimization of the water supply circuit, and implementation of the Pastormaster method. Water samples were taken at 10 representative points in the hospital hot-water system and cultured microbiologically. Other physical and chemical measurements were also determined. Implementation of the Pastormaster method and correction of the deficiencies identified during a hydraulic system audit confirmed the absence of legionella in the hospital water distribution system. The combination of implementation of the Pastormaster method and conduction of a hydraulic audit designed to identify and remedy any possible problems in water circulation is effective in minimizing the risk of legionella contamination in hospital water distribution systems.