Anastomotic leakage (AL) during Ivor-Lewis esophagectomy (ILE), owing to gastric conduit (GC) ischemia, is a serious complication. Measurement parameters during intraoperative ICG fluorescence angiography (ICG-FA) are unclear. We aimed to identify objective ICG-FA parameters associated with AL. Patients > 18 years with an indication for ILE were enrolled. ICG-FA was performed at the abdominal and thoracic stage, and data, such as time of fluorescence appearance, speed of ICG perfusion, quality of GC perfusion (good, poor, ischemic), blood pressure, baseline patient characteristics, GC dimensions, and other intraoperative parameters were collected. On postoperative day 4 to 6, Gastrografin swallow radiography was performed. AL development was classified based on the Clavien–Dindo and SISG severity classifications. Univariate analysis with a 95% confidence level (p