Neurilemmoma of the stomach is a rare controversial neoplasm which requires extensive studies to clarify its nature from stromal tumor or leiornyoma. This paper describes the pathologic, immunohistochemical and ultrastructural characteristics of neurilemmoma of the stomach from a 52-year-old woman. The tumor was a 2.2cm, well circumscribed submucosal mass located in the anterior wall of midbody. Microscopically, the cells were made up of fasciculating bundles of spindle cells featured with benign nuclear atypia and peripheral lymphoid cell cuffing. The tumor cells revealed a diffuse strong immunoreactivity to S-100 protein and vimentin, but were negative to desmin and smooth muscle actin, and focal positive reaction to glial fibrillary acidic protein. Peripheral lymphoid cuffing was suggested an immune reaction against the tumor tissue. Ultrastructurally, rnany tumor cells showed a number of thin e]ongated and interdigitating dendritic- like cell processes, distinct uniform basal laminae, frequent cellular attachments and microfila- ments. The findings supported the schwannian nature of the tumor, and the focal positive immunoreactivity for GFAP indicates the possibility of focally modified schwann cell. (Korean J Gastroenterol 1996;28:556 - 560)