Purpose of this study is to evaluate the visualization of endoscopic ultrasonography (EUS) in the ileocecal area using ultrasonic probe. Subjects are 36 lesions in the cecum (18 : aggregated nodular granular lesion (ANGL) , 10 : submucosal tumor, 8 : advanced cancer) and 4 lesions in the terminal ileum (advanced cancer, intestinal Behçet's disease, simple ulcer and benign lymphoid hyperplasia, respectively) . EUS was performed using ultrasonic probe for 3 year and 8 months, from June 1993 to February 1997. For ANGLs located in the bottom of cecum (3 of 6 lesions) and in the inner side of cecum connected to the ileocecal valve (1 lesion) , their layer structure could not be visualized clearly. On the other hand, for ANGLs located in the opposite side of the ileocecal valve (8 of 10 lesions) and in the superior side of the ileocecal valve (1 lesion) , their clear layer structure could be visualized easily. Submucosal tumors and advanced cancer in the cecum could be diagnosed and visualized the depth of invasion and para colonic lymphnode swelling clearly. For the lesions in the terminal ileum, EUS were also useful for diagnosis. In conclusion, EUS using ultrasonic probe was useful for diagnosis in the ileocecal area, but the lesions located in the particular part of cecum could not be visualized clearly.