Objective To investigate whether exercise stress myocardial perfusion imaging (MPI) with technetium-^99m-labelled methoxyisobutyl isonitrile single photon emission computed tomography (^99mTc-MIBI SPECT) has value in the prediction of major adverse cardiovascular events (MACEs) in the patients with type 2 diabetes mellitus who are suspected of myocardial ischemia. Methods A retrospective study was carried out on 165 diabetic patients who were suspected of myocardial ischemia and underwent ^99mTc-MIBI SPECT stress MPI in our department from June 2013 to March 2016. According to summed stress score (SSS), the patients were divided into SSS 0-7 group and SSS ≥8 group. The survival and incidence of MACEs were followed up after discharge by telephone. Clinical data were analyzed by SPSS statistics 17.0. The differences were compared with t test, rank-sum test or Chi-square test respectively. Results Significant differences were observed in proportion of males, body mass index (BMI), left ventricular ejection fraction (LVEF), left ventricular end systolic diameter (LVESD), typical angina, revascularization, wall motion abnormalities, incidence of MACEs and hospitalization rate due to angina between the 2 groups (P<0.05). Cox univariate regression analysis showed that ventricular wall motion abnormalities, increased SSS, family history of coronary heart disease, previous history of vascular remodeling, old myocardial infarction are risk factors for MACEs. Cox multivariate regression analysis indicated that the family history of coronary heart disease (RR=2.964,5%CI 1.318-6.666, P=0.009) was a risk factor for MACEs, and the other variables had no predictive effect. Kaplan-Meier survival analysis showed that the incidence of MACEs was 1% in the SSS 0-7 group and 4% in the SSS ≥8 group, with the cumulative survival rate higher in the former than the latter group (P=0.005). Conclusion ^99mTc-MIBI SPECT stress MPI can be used for risk stratification and prognosis assessment in the diabetic patients with suspected myocardialischemia. Vascular reconstruction can be recommended for those high-risk patients with SSS ≥8.