INTRODUCTION The prognostic value of coronary artery calcium score (CACS) in symptomatic patients with a suspicion of coronary artery disease (CAD) has been poorly defined. OBJECTIVES The aim of the study was to assess the predictive value of the CACS in the incidence of major adverse coronary events (MACEs) in patients with an intermediate probability of CAD and establish its usefulness as the first-line risk assessment tool. PATIENTS AND METHODS This single-center, observational, prospective study enrolled consecutive symptomatic patients without a previous diagnosis of CAD, referred to our center for CACS assessment with non-contrast-enhanced cardiac computed tomography (CT). CACS measurements were performed using an electrocardiogram-gated 64-row CT scanner. The CACS measurement was treated as the first‑line noninvasive test. Patients with positive CACS values were divided into 4 subgroups: <100 Agatston units (AU), 100 to 399 AU; 400 to 999 AU; and ≥1000 AU. The incidence of MACEs was analyzed in 2 ways: negative versus positive CACS and by the CACS subgroups. RESULTS We included 588 patients (mean age, 61.1 ±9.7 years; women, 64%). The median follow-up period was 707 days. There were 239 patients (49.3%) with no coronary calcium. In these patients, no MACEs were observed, while in those with positive CACS values, they occurred in 108 patients (30.9%) (P <0.001). The incidence of MACEs was dependent on the CACS values, reaching 91% in those with a CACS of 1000 or higher AU. CONCLUSIONS In selected symptomatic patients with an intermediate probability of CAD, the CACS measurement may be used as the first-line test to assess the risk of MACEs.