Gastric schwannomas are rare benign neurogenic mesenchymal tumors that are usually asymptomatic but can present with variable symptoms. We retrospectively reviewed the endosonographic features of four patients with gastric schwannomas. A marginal hypoechoic halo was found in three patients with the schwannomas. The histopathological examination showed that the marginal halo on endosonography observed in the schwannomas corresponded to the lymphoid cuff. In addition, the schwannomas had lower echogenicity than the normal surrounding muscle layers. Therefore, these results suggest that gastric schwannomas can be differentiated from gastrointestinal stromal tumors by the marginal halo and the homogeneous hypoechoic endosonographic findings. These distinctions may be useful for the preoperative evaluation of gastric submucosal tumors.