Objective: Cardiac guidelines recommend that the decision to perform coronary angiography (CA) in patients with Non-ST-Elevation Acute Coronary Syndrome (NST-ACS) is based on multiple factors. It is, however, unknown how cardiologists weigh these factors in their decision-making. The aim was to investigate the importance of different clinical characteristics, including information derived from risk scores, in the decision-making of Dutch cardiologists regarding performing CA in patients with suspected NST-ACS. Design: A web-based survey containing clinical vignettes. Setting and participants: Registered Dutch cardiologists were approached to complete the survey, in which they were asked to indicate whether they would perform CA for 8 vignettes describing 7 clinical factors: age, renal function, known coronary artery disease, persistent chest pain, presence of risk factors, ECG findings and troponin levels. Cardiologists were divided into two groups: group 1 received vignettes 'without' a risk score present, while group 2 completed vignettes 'with' a risk score present. Results: 129 (of 946) cardiologists responded. In both groups, elevated troponin levels and typical ischaemic changes (p<0.001) made cardiologists decide more often to perform CA. Severe renal dysfunction (p<0.001) made cardiologists more hesitant to decide on CA. Age and risk score could not be assessed independently, as these factors were strongly associated. Inspecting the factors together showed, for example, that cardiologists were more hesitant to perform CA in elderly patients with high-risk scores than in younger patients with intermediate risk scores. Conclusions: When deciding to perform in-hospital CA (≤72 hours after patient admission) in patients with suspected NST-ACS, cardiologists tend to rely mostly on troponin levels, ECG changes and renal function. Future research should focus on why CA is less often recommended in patients with severe renal dysfunction, and in elderly patients with high-risk scores. In addition, the impact of age and risk score on decision-making should be further investigated.