Coronary function testing (CFT) plays a pivotal role in the diagnosis of coronary vascular dysfunction and in providing patients with tailored therapy. The Belgian registry on coronary function testing (BELmicro registry) is a prospective, observational, multicenter registry including 14 centers in Belgium. All patients undergoing clinically indicated CFT were included in the registry. Baseline characteristics, CFT data, and clinical outcomes were collected. The aims of the current analysis were to describe the baseline characteristics of a real-world population of patients undergoing CFT, to evaluate the prevalence of coronary vascular dysfunction and to assess the safety of CFT in daily clinical practice. Between October 2021 and September 2023, 449 patients were enrolled. The mean age was 65 ± 10 years, and 47.4% of patients were male. Fifty-nine percent of patients had hypertension, 18.7% diabetes, 69.5% hypercholesterolemia, and 40.1% smoking habit. Angina and non-obstructive coronary arteries (ANOCA) were identified in 85.1% of patients. Microvascular physiology assessment was performed in 95.5% of patients, vasoreactivity test in 28.5%, and both in 24.0%. CMD was diagnosed in 23.4% of ANOCA patients, epicardial vasospasm in 26.3%, and microvascular spasm in 14.9%. Rates of major complications were 0.7% for microvascular physiology assessment and 0% for vasoreactivity test. In conclusion, participants in the BELmicro registry represented a real-world population of patients, characterized by a high burden of cardiovascular risk factors. Both CMD and coronary vasospasm were frequent in ANOCA patients. Performing CFT in daily clinical practice was feasible with a low rate of complications.