Background Noninvasive cardiac imaging is now central to the diagnosis and management of patients with moderate probability for coronary artery disease. The aim of this study was to assess the impact of stress myocardial perfusion single photon emission computerized tomography (SPECT) on in-hospital coronary angiography and revascularization for such patients.Methods Between January 2005 and June 2007, 1053 consecutive in-hospital patients (423 women, the average age of (57.2±11.2) years) with suspected coronary artery disease but without any prior interventional treatment were retrospectively analyzed. All patients underwent a 2-day stress/rest 99m Tc-methoxyisobutylisonitrile (MIBI) myocardial perfusion SPECT, including 984 exercise test and 69 adenosine test.Results Overall, stress/rest myocardial perfusion SPECT was normal in 973 patients (92.4%) and abnormal in 80 patients (7.6%). A total of 190 patients underwent coronary angiography, 46 underwent percutaneous coronary intervention and 10 coronary artery bypass grafting during hospitalization. From the whole perspective, only 14.7% of patients with normal SPECT underwent coronary angiography, so did 58.8% of patients with abnormal SPECT (x2=97.0,P＜0.001); furthermore, the rates of revascularization in patients with normal and abnormal SPECT were 2.8% and 36.3%,respectively (27 out of 973 vs. 29 out of 80, x2=157.9, P＜0.001). The extent and severity of ischemia did not add more predictive value for subsequent coronary angiography, but did have impact on revascularization. Multivariate analysis showed that reversible perfusion defect was the most predictive variable for referral rate to coronary angiography (odds ratio=7.5, P＜0.001).Conclusions Abnormal myocardial perfusion SPECT is a powerful referral for in-hospital coronary angiography and revascularization during the same hospitalization. Thus, stress/rest SPECT is an effective gatekeeper for early coronary angiography and invasive treatment for patients with suspected coronary artery disease.