Intraoperative identification of the cancer location is often difficult during robot-assisted surgery, especially in early stage cancers. This study aimed to investigate the feasibility and accuracy of a novel endoscopic clip emitting near-infrared (NIR) fluorescence during robot-assisted surgery for gastrointestinal cancer. Preoperative placement of endoscopic marking clips equipped with NIR fluorescent resin was performed to determine the resection margins in six patients with gastrointestinal cancer. During robot-assisted surgery, a NIR fluorescence imaging system was used to detect the fluorescence. The evaluation examined whether fluorescence from the clips was visualized during robot-assisted surgery. The NIR fluorescent signals emitted from the clips were successfully detected in all six patients from the serosal surfaces, resulting in the quick and accurate identification of the resection line. There were no significant differences in age, sex, or body mass index between the patients in whom we could detect NIR fluorescence. This novel NIR fluorescent clip is a promising diagnostic tool for accurately detecting tumor locations during robot-assisted surgery for gastrointestinal cancer.