Background: Most cancers and adenomas of the GI tract are easily detected by light-induced fluorescence endoscopy (LIFE-GI). However, some tumors are poorly visualized by using this technique. To investigate whether the spraying of noradrenaline on the lesion provides better visualization of the boundaries of neoplasms, the conventional and LIFE-GI endoscopic observations were made before and after spraying of nonadrenaline. Methods: Seven patients with gastric cancers were studied. After a conventional fiberscopic examination, a LIFE-GI procedure was performed, and then 20 mL of 0.02% noradrenaline solution was sprayed on the lesion. Results: The normal mucosa became paler than the tumor after spraying noradrenaline, thereby clarifying the tumor boundary in the LIFE-GI image. Conclusions: The combined use of pharmacoendoscopy with LIFE-GI is useful in the detection of gastric malignant tumors because it enhances the boundaries of these lesions.