Double-inlet left ventricle (DILV) is a congenital heart disease that only a single left ventricle and a rudimentary right ventricle are developed. Because of lack of anatomic landmark, interpretation of 201Tl myocardial perfusion imaging in DILV is essentially challenging for unusual anomaly. We report the case of a 44-year-old woman with DILV who presented exertional dyspnea and tachycardia and underwent 201Tl SPECT. The anatomic characteristics of cardiac 201Tl SPECT are correlated with MRI. To obtain accurate interpretation in DILV, it is absolutely necessary to realize the anatomy relationship between perfusion imaging and anatomic imaging such as CT or MRI.