Nerve damage during surgery is a common and serious complication, often leading to chronic pain, functional impairments, and diminished quality of life. However, existing methods for intraoperative nerve identification remain insufficient, especially for detecting small or hidden nerve branches. Here we present a new application of a clinically approved fluorescent agent, sodium fluorescein, to enhance nerve visualization during surgery. Utilizing both clinical and customized imaging systems, fluorescein remarkably improved nerve contrast, revealing structures undetectable with white light, including small branches embedded within tissues. With its established safety profile, low cost, and immediate clinical applicability, sodium fluorescein offers the potential to revolutionize surgical practice by minimizing nerve injuries and improving patient outcomes. Clinical Trial Registration: NCT06054178 .