The aim of the present study was to: (i) document the prevalence of risk factors for non-communicable diseases among mental health consumers (inpatients) with various diagnoses; and (ii) audit the frequency of waist circumference (WC) documentation before and after an intervention that involved a single nurse-education session, and change in assessment-form design. The study was undertaken in a private psychiatric hospital in Sydney, Australia. Twenty-five nurses participated in the educational intervention. File audits were performed prior to intervention delivery (n = 60), and 3 months' (n = 60), and 9 months' (n = 60) post-intervention. Files were randomly selected, and demographic (age, diagnosis) and risk factor (WC, body mass index (BMI), smoking status, blood pressure) data were extracted. WC was higher in this cohort compared to published general population means, and only 19% of patients had a BMI within the healthy range. In total, 37% of patients smoked, while 31% were hypertensive. At baseline, none of the audited files reported WC, which increased to 35 of the 60 (58%) files audited at the 3-month follow up. At the 9-month follow up, 25 of the 60 (42%) files audited reported a WC. In the 120 post-intervention files audited, only two patients refused measurement. These results illustrate the poor physical health of inpatients, and suggest that nurse-assessed metabolic monitoring can be enhanced with minimal training.