<b><i>Objectives:</i></b> In the recently updated clinical guidelines from the European Society of Cardiology on the management of stable coronary artery disease (CAD), the updated Diamond Forrester score has been included as a pretest probability (PTP) score to select patients for further diagnostic testing. We investigated the validity of the new guidelines in a population of patients with acute-onset chest pain. <b><i>Methods:</i></b> We examined 527 consecutive patients with either an exercise-ECG stress test or single-photon emission computed tomography, and subsequently coronary computed tomography angiography (CCTA). We compared the diagnostic accuracy of PTP and stress testing assessed by the area under the receiver operating characteristic curve (AUC) to identify significant CAD, defined as at least 1 coronary artery branch with >70% diameter stenosis identified by CCTA. <b><i>Results:</i></b> The diagnostic accuracy of PTP was significantly higher than the stress test (AUC 0.80 vs. 0.69; p = 0.009), but the diagnostic accuracy of the combination of PTP and a stress test did not significantly increase when compared to PTP alone (AUC 0.86 vs. 0.80; p = 0.06). <b><i>Conclusions:</i></b> PTP using the updated Diamond and Forrester Score is a very useful tool in risk-stratifying patients with acute-onset chest pain at a low-to-intermediate risk of having CAD. Adding a stress test to PTP does not appear to offer significant diagnostic benefit.