This short paper looks at the risks that Pseudomonas aeruginosa infections pose to our most vulnerable patients; not only the direct effects of infection, but also its role in spreading antimicrobial resistance in our hospitals.. Environmental testing for the bacterium in relation to hospital water services is recommended in national guidance as part of the overall control strategy. This paper looks at some of the potential pitfalls associated with this type of testing, and offers insights into how testing can be achieved more cost effectively and with greater assurances of patient safety.