OBJECTIVE To investigate the relation of 5 major risk factors (hypertension, diabetes, hyperlipidemia, overweight, smoking) of coronary artery disease (CAD) to the findings from thallium-201 single photon emission computed tomography. METHODS Exercise 201TI myocardial scintigraphy was performed in 346 patients with clinically suspected CAD, who were divided into no risk, low risk, moderate risk, and high risk groups, based on CAD risk scores. RESULTS The rate of thallium-201 perfusion abnormalities in no risk, low risk, moderate risk, and high risk groups were 48.1%, 70.6%, 89% and 100%, respectively, showing significant difference between them (X2=49.6, P=0.000 1). In patients with CAD risk factors, significant relation was found between the risk scores and semiquantitative scores, lung-to-heart ratios or segment abnormalities (0.133 r 0.450, 0.000 1 P 0.031). CONCLUSIONS A close relation between CAD risk factors and thallium-201 myocardial scintigraphy is found. Routine thallium-201 myocardial scintigraphy should be performed in patients clinically suspected of coronary artery disease with CAD risk factors, especially those with moderate to high risk factors.