Aims We sought to determine the diagnostic performance, clinical profiles and outcomes of anomalous aortic origin of coronary arteries (AAOCA) using a standardised echocardiographic approach in young adults and athletes.Methods In 2015–2019, we screened 5998 outpatients (age 16 years (Q1–Q3: 11, 36)), referred for routine echocardiography, using four specific echocardiographic windows: parasternal short/long axis and apical 4/5-chambers view. Coronary CT confirmed AAOCA. For the performance analysis, 300 coronary-CT scans were available; two independent and double-blinded physicians retrospectively reviewed echocardiographic images.Results A total of 47 AAOCA was diagnosed; the overall prevalence was 0.0078%. Over 5 years, we found a significant increment of AAOCA diagnostic rate (P for trend=0.002). Syncope (n=17/47) and palpitations (n=6/47) were prevalent symptoms. All patients suspended sports activity at the diagnosis. Twenty-seven patients underwent surgery, while 20 underwent a conservative medical treatment. All patients are alive at a median follow-up of 3±1.6 years; only surgical repairs restarted their activity. Our method showed better sensitivity than traditional short-axis evaluation: 93% vs 83%, p=0.0030 (AUC 0.96 (95% CI 0.92, 0.99) and AUC 0.89 (95% CI 0.83, 0.95), respectively), with a good interobserver agreement (95%, k=0.83, p