We report endonasal ultrasonography (US)-assisted neuroendoscopic transsphenoidal surgery (TSS) in seven patients. With sagittal and coronal US images, internal carotid arteries, anterior cerebral arteries, residual tumor, and lateral ventricles were recognized, and the tumors were removed without leakage of cerebrospinal fluid in patients with pituitary adenoma. US images clearly depicted the carotid arteries, anterior cerebral arteries, middle cerebral arteries, chiasmatic cistern, and residual tumor. Endonasal US images can provide real-time animated information and may help neuroendoscopic TSS, whenever needed during TSS.