BACKGROUND Priapism is a persistent penile erection that lasts longer than 4 hours. The most common causes of priapism are ischemia and the effects of drugs, including PDE-5 inhibitors, such as sildenafil and anticoagulants. Here, we describe the presentation and management of a 50-year-old man with priapism following coronary artery angiography for the investigation of ischemic heart disease (IHD). CASE REPORT A 50-year-old man was admitted to the Department of Cardiovascular Disease with the chief concern of intermittent precordial pain and discomfort for 1 year. After performing regular medical tests in the hospital, we confirmed that there was a need to identify the cause of the chest pain. Thus, after obtaining informed consent, we performed coronary angiography and diagnosed the patient with coronary artery disease based on the results of coronary angiography. However, half an hour after coronary angiography, he developed priapism. By performing ultrasound of the penis, we found that there was a thrombus in the penile vein. By combining blood aspiration from the corpus cavernosum of the penis with injection of hydroxylamine into the corpus cavernosum, we achieved a good treatment effect. CONCLUSIONS Priapism is becoming more common in middle-aged men. It should be treated as a medical emergency according to current management guidelines, and the underlying cause should be identified to prevent recurrence.