Background: The FRISC-II invasive trial compared an early invasive with a non-invasive strategy in terms of death and myocardial infarction in non-ST-elevation acute coronary syndrome. We present 5-year follow-up results, overall and in subgroups based on recommended risk stratification criteria. Methods: In the FRISC-II trial, 2457 patients with non-ST-elevation acute coronary syndrome were randomised to early invasive strategy (coronary angiography and, if appropriate, revascularisation, within 7 days from admission) or non-invasive primarily medical strategy. Risk stratification was done on the basis of risk indicators at randomisation: age older than 65 years, male sex, diabetes mellitus, previous myocardial infarction, ST-segment depression, raised troponin concentration (>0·03 μg/L), and raised C-reactive protein or interleukin 6. Information on events after 24 months was taken from national registries. Analyses were done on an intention-to-treat basis. Findings: At 5 years the groups differed in terms of the primary composite endpoint of death, myocardial infarction, or both (invasive 217, 19·9 %, noninvasive 270, 24·5 %, risk ratio 0·81, 95% CI 0·69-0·95, p=0·009). 5-year mortality was 117 (9·7%) in the invasive group compared with 124 (10·1%) in the noninvasive group (0·95, 0·75 -1·21, p=0·693). Rates of myocardial infarction were 141 (12·9 %) in the invasive and 195 (17.7%) in the non-invasive group (0·73, 0·60-0·89, p=0·002). The benefit of the invasive strategy was confined to male patients, non-smokers, and patients with two or more risk indicators. Interpretation: The 5-year outcome of this trial indicates sustained benefit of an early invasive strategy in patients with non-ST-elevation acute coronary syndrome at moderate to high risk. © 2006 Elsevier Ltd. All rights reserved.