Microsurgical subinguinal varicocelectomy is one of the best treatment modalities for varicoceles. However, the difficulty in identifying testicular arteries that should be spared is a limitation of this technique. We assessed the efficacy of intraoperative indocyanine green angiography (ICGA) during microsurgical subinguinal varicocelectomy in three pilot cases. We performed microsurgical subinguinal varicocelectomy using a surgical microscope for observing infrared fluorescence in patients with infertility or chronic pain associated with varicoceles. After the exposure of the spermatic cord blood vessels, ICG was injected intravenously to identify and isolate the testicular artery. Thereafter, the varicose veins were repeatedly ligated, while preserving a few lymphatic vessels and the spermatic duct. The testicular artery could be clearly identified by ICGA and were able to separate under ICGA. The preserved arteries were confirmed by ICGA at the end of microsurgical operation. Though, all the internal spermatic veins could be safely ligated, while sparing the testicular arteries and lymphatic vessels. Microsurgical subinguinal varicocelectomy using intraoperative ICGA facilitated safe and quick surgery by enabling the visualization of the spermatic cord blood vessels. This is the first report to indicate the usefulness of vessel visualization by ICGA during microsurgical subinguinal varicocelectomy.