Patients with mental illness have an increased risk of cardiovascular morbidity. The Swedish-developed Health Dialogue is a pedagogical tool to individualize lifestyle counselling, used in specific age-groups to improve lifestyle habits and decrease mortality, but not tested specifically for patients with mental illness. Patients > 18 years old seeking primary care due to symptoms related to mental illness and diagnosed with depression, sleeping disorders, stress and anxiety, were included. A nurse-led health dialogue was conducted, focusing on lifestyle habits, anthropometric measurements, and blood samples, resulting in tailored advice regarding the individual’s risk profile. All 64 participants had lifestyle areas with increased risk level. Approximately 20% had elevated fasting glucose, blood pressure or cholesterol levels, and over 40% had highest risk level in Waist–Hip-Ratio. 30% were overweight, or physical inactive. The results suggest the need of a larger cohort study with long-term follow up, to establish potentially positive effects on wellbeing, and decreased cardiovascular risk in patients with mental illness.Clinical trial registration: The study was registered at ClinicalTrials.gov January 6th, 2022, registration number NCT05181254.