OBJECTIVE In a double-blind randomized trial in unstable angina it was shown that intravenous diltiazem reduced ischaemic events in the first 48 h after inclusion better than intravenous nitroglycerin. The present study was performed to establish the long-term prognosis of the randomized patients, with respect to their initial treatment assignment. RESULTS One year follow-up data on ischaemic end-points and anti-ischaemic medication were recorded. Results were available for all of the 121 randomized patients. One hundred and sixty-seven primary endpoint events were recorded, of which 54 occurred in the first 48 h and 113 during the follow-up. Survival analysis showed that event-free survival was significantly better in the diltiazem group (45.0%) than in the nitroglycerin group (34.4%), P=0.04. The incidence rate after 48 h and one year for cardiac death are, respectively, 0% and 4.1%. The trend in anti-ischaemic medication was higher in the nitroglycerin group. For beta-blockers, this trend became significant after 12 months (P=0.03). CONCLUSIONS These results show that the initial benefit obtained by early treatment with intravenous diltiazem was preserved during the first year after the initial hospitalization, and that, despite the high risk of cardiac events in our population, the overall mortality 12 months after inclusion was low.