Objectives. To evaluate the association between glycometabolic status in the acute phase and 2½ years later in patients with acute coronary syndrome (ACS). Methods. Non-diabetic patients (n = 762) presenting with ACS were prospectively followed up for 2½ years. Patients were stratified by admission plasma glucose (<6.1 mmol/l, 6.1 – 6.9 mmol/l and ≥7.0 mmol/l) and HbA1c (≤4.5%, 4.6 – 5.4% and ≥5.5%). The predictive value of glucose levels ≥ 7.0 mmol/l and HbA1c ≥ 5.5% for glycometabolic disturbance (i.e. diabetes or impaired fasting glycaemia (IFG)) was analysed. Results. Of 762 patients, 13% had a diagnosis of diabetes and 16% had IFG at follow-up. The prevalence of glycometabolic disturbance at follow-up increased with increasing plasma glucose at admission, from 19% in patients with < 6.1 mmol/l to 42% in patients with ≥ 7.0 mmol/l. Sixty-one percent of patients with HbA1c ≥ 5.5% had glycometabolic disturbance after 2½ years compared to only 25% of those with HbA1c < 5.5%. Conclusion. Non-diabetic patients with ACS and hyperglycaemia are at high risk for developing glycometabolic disturbance. HbA1c may be an even stronger predictor of glycometabolic disturbance than plasma glucose.