People with serious mental illness have significantly poorer physical health compared to the general population. Mental health nurses are in a prime position to help reduce unacceptable death in this population. A literature search was undertaken to identify the role of the mental health nurse in regards to physical health care, intervention, and attaining the necessary knowledge to address the physical health needs of people in the UK with serious mental illness. Of 254 papers identified, nine met the inclusion criteria. An integrative literature review found that mental health nurses are not routinely supported by physical health-care education and training, with many expressing role ambiguity. Inpatient setting correlated to a less positive role attitude; poor primary–secondary care interface communication compounded the problem of this vulnerable population having their physical health needs identified and met.