Coronary computed tomography angiography (CCTA) appears comparable to standard care, including exercise stress testing (EST), in diagnosing acute coronary syndrome in emergency department (ED) patients with chest pain but may increase downstream testing. The objective of this study was to investigate rates of post-CCTA versus post-EST testing for (1) invasive angiography and (2) all combined cardiac testing. This was a retrospective cohort study performed at 2 urban Canadian EDs involving patients aged up to 65 years with chest pain but no objective ACS findings that were evaluated with CCTA or EST at the physician's discretion. The primary outcome was the proportion of patients who had 30-day invasive angiography in each group; secondary outcomes included all subsequent 30-day cardiac testing, including nuclear medicine scanning. From July 1, 2012, to June 30, 2014, we collected 1,700 patients: 521 CCTA and 1,179 EST. Demographics and risk factors were similar in both cohorts. In the following 30 days, 30 CCTA (5.8%) and 297 EST (25.2%) patients underwent any type of additional cardiac testing (difference 19.4%, 95% CI 16.0 to 22.6), whereas 12 CCTA (2.3%) and 20 EST patients (1.7%) underwent angiography (difference 0.6%, 95% CI -0.8% to 2.6%). No patients in either group died or had a myocardial infarction within 30 days. For ED patients with chest pain who underwent brief observation, CCTA and EST had similar 30-day angiography rates, but CCTA patients underwent significantly less overall cardiac investigations.