Although survival after heart transplantation (HTx) has improved in recent years, cardiac allograft vasculopathy (CAV) is still the leading cause of remote morbidity and mortality in HTx recipients, partly because of difficulty with its diagnosis. In general, routine surveillance for CAV is advocated with coronary angiography accompanied by intravascular ultrasound (IVUS) if necessary. However, these modalities have limitations with respect to low spatial resolution, and sufficient qualitative/quantitative assessment of coronary intima has not been accomplished. Recently, optical coherence tomography (OCT) has emerged as a novel intracoronary imaging technique using an optical analogue of ultrasound with a spatial resolution of 10-20 µm, which is 10 times greater than IVUS. We here experienced a 49-year-old male who received a HTx 3 years ago, and OCT was executed during low molecular weight dextran injection. OCT demonstrated distinct double intimal layers probably consisting of a donor-transmitted atherosclerotic layer and an inner intimal proliferation due to CAV, which was indistinguishable by IVUS and virtual histological analyses. We believe that OCT imaging is not only a new loadstar during treatment of CAV but also a new generation modality for screening for early CAV in HTx recipients.