Purpose: Tc-99m-tetrofosmin(TF) is a recently proposed myocardial imaging agent which has similar biokinetic characteristics to Tc-99m-sestamibi(MIBI). The aim of this study was to compare TF and MIBI myocardial perfusion SPECTs in detecting coronary artery disease. Materials and Methods: One hundred and sixty patients(l0l males, 59 females, mean age 57±9 yr) who had undergone both myocardial perfusion SPECT (M- SPECT) and coronary angiography within 1 month were studied. M-SPECT was performed using TF in 115 patients and MIBI in 45 patients. Stress-rest one day protocol was used in all patients A coronary stenosis was considered significant when the luminal diameter ≥50% was compromised. The chi square test was used to compare, differences in sensitivity and specificity between the two groups. Results: There was no difference in age and diseased coronary artery branches between the two groups. There were more male patients in TF group: Male-to-female ratios of TF and MIBI groups were 78:37 and 23:22, respectively (p〈0.05). The overall sensitivity of TF study was 92% and specificity 36%. The overall, sensitivity and specificity of MIBI study were 93% and 30% respectively. There was no difference between TF and MIBI groups in identifying individual diseased coronary artery branches. Conclusion: One day stress-rest myocardial SPECT using either TF or MIBI was comparable and was a very sensitive test in detecting coronary artery disease.