Abstract. The present study aimed to discuss and evaluate the diagnostic performances and incremental clinical values of combined computed tomography coronary angiography (CTCA) and single photon myocardial perfusion imaging (MPI) for the detection of functionally relevant coronary stenoses (FRCS). In total, 54 patients underwent CTCA, MPI and coronary angiography (CAG) within 30 days. The diagnostic performances of CTCA and combined CTCA plus MPI for the detection of significant coronary stenoses (≥50%) were calculated on the patient-or vessel-based levels and included the indices of sensitivity (SN), specificity (SP), positive predictive value (PPV), negative predictive value (NPV) and accuracy (AC). On the patient-based level, the SP, PPV, NPV and AC of CTCA alone or combined with MPI in the detection of FRCS were 90.9 and 90.9, 71.9 and 96.9, 69.0 and 95.2, 92.0 and 93.9 and 79.6 and 94.4%, respectively. On the vessel-based level, the SN, SP, PPV, NPV and AC of CTCA alone or combined with MPI in the detection of FRCS were 90.3 and 90.3, 87.6 and 98.9, 54.9 and 93.3, 98.2 and 98.4 and 88.0 and 97.7%, respectively. The PPV, SP and AC of combined CTCA and MPI in the detection of FRCS were significantly improved compared with CTCA alone (all values, P<0.05). The diagnostic performance of combined CTCA and MPI in the detection of FRCS not only retains a high SN and NPV, but also markedly improves SP, PPV and AC, which should play an incremental and significant role in the decision-making process for the revascularization therapy of coronary artery disease (CAD).