Mental illness affects one in five Australians in any given year and depression, anxiety and substance abuse are the most prevalent of the mental health problems. Mental illness is traditionally managed with medication and psychological intervention but exercise and diet have also been shown to be related to mental illness and are associated with improvements in mental health. The present article aims to describe the background and practical issues arising from the establishment of diet and exercise assessments and intervention for people receiving treatment for depression and anxiety in general practice settings. Patients were referred by their general practitioners, and attended sessions either in rooms at their practitioner's surgery or at a central clinic location. The program involved an initial assessment, four individual consultations with a dually qualified dietitian and exercise physiologist, and a final assessment. Issues in the process of assessing mental health, diet quality, physical fitness and physical activity behaviours are described as are key components of the tailored treatment programs. Strategies for improving motivation and adherence such as adjusting frequency of sessions, use of homework and means of communication are highlighted.