Objective To determine the effect of percutaneous coronary intervention (PCI) guided by intravascular ultrasound (IVUS) on the prognosis of non-ST segment elevation acute coronary syndrome (NSTE-ACS) patients with intermediate lesions. Methods A total of 100 NSTE-ACS with intermediate lesions patients allowing elective PCI indicated by coronary angiography (CAG) in our department from June 2016 to January 2017 were recruited in this study. They were randomly divided into IVUS group and fractional flow reserve (FFR) group, with 50 cases in each group. All patients were followed up for 12 months, and the incidence of major adverse cardiovascular events (MACEs) was compared between the 2 groups. Results There were no significant differences in the diameter of lesion vessel [(3.5±0.7) vs (3.0±0.5)mm], degree of stenosis [(62.6±5.0)% vs (57.2±7.5)%], lesion length [(20.2±8.8) vs (23.5±10.7)mm], and the incidence rates of PCI-related complications [8.0%(4/50) vs 4.0%(2/50)] between the IVUS group and FFR group (P>0.05). The stent implantation rate was higher in the IVUS group than the FFR group [56.0%(28/50) vs 38.0%(19/50)], though without statistical difference (P>0.05). There was no significant difference in the incidence of MACEs in 12 months after surgery between the 2 groups [18.8%(9/48) vs 14.3%(7/49), P=0.55]. ConclusionFor the NSTE-ACS patients with intermediate lesions, IVUS is not inferior to FFR in the guidance of revascularization therapy for the short-term prognosis.