Background: This study aimed to increase cardiovascular disease (CVD) risk assessment in adult first degree relatives of patients with premature ischaemic heart disease (PIHD) using written and verbal advice. Methods: Design: A prospective, randomised controlled trial. Setting: Cardiovascular wards at three South Australian hospitals. Cardiovascular risk assessments were performed in general practice. Participants: Patients experiencing PIHD (heart disease in men aged <55 years or women aged∈<∈65 years) and their first degree relatives. Intervention: Patients distributed either general information about heart disease and written advice to attend their general practitioner (GP) for CVD risk assessment or general information about heart disease only, to their first degrees relatives. Main outcome measure: The primary outcome was the proportion of relatives who attended their GP for CVD risk assessment within 6 months of the patients' PIHD event. Results: One hundred forty four patients were recruited who had 541 eligible relatives; 97/541 (18 %) of relatives agreed to participate. A larger number of intervention 41/55 (75 %) than control group 9/42 (21 %) [difference 53 %, 95 % CI 36 % - 71 %] relatives attended their GP for a CVD assessment, and 34 % of these had moderate to very high 5-year absolute risk for CVD. Conclusion: This low cost intervention demonstrates that individuals who have a family history of PIHD and are at moderate or high risk of CVD can be targeted for early intervention of modifiable risk factors. Further research is required to improve the uptake of the intervention in relatives. Trial registration: The trial was registered with the Australian Clinical Trials Registry (ACTRN), Registration ID 12613000557730.