The life expectancy of people with severe mental illnesses is substantially reduced, and monitoring and screening for physical health problems is a key part of addressing this health inequality. Inpatient admission presents a window of opportunity for this health‐care activity. The present study was conducted in a forensic mental health unit in England. A personal physical health plan incorporating clearly‐presented and easily‐understood values and targets for health status in different domains was developed. Alongside this, a brief physical education session was delivered to health‐care staff (n = 63). Printed learning materials and pedometers and paper tape measures were also provided. The impact was evaluated by a single‐group pretest post‐test design; follow‐up measures were 4 months’ post‐intervention. The feasibility and acceptability of personal health plans and associated resources were examined by free‐text questionnaire responses. Fifty‐seven staff provided measures of attitudes and knowledge before training and implementation of the physical health plans. Matched‐pairs analysis indicated a modest but statistically‐significant improvement in staff knowledge scores and attitudes to involvement in physical health care. Qualitative feedback indicated limited uptake of the care plans and perceived need for additional support for better adoption of this initiative. Inpatient admission is a key setting for assessing physical health and promoting improved management of health problems. Staff training and purpose‐designed personalized care plans hold potential to improve practice and outcomes in this area, but further support for such innovations appears necessary for their uptake in inpatient mental health settings.