40 patients were examined by peroral endoscopic ultrasonography with two new prototypes (Prototype II and III, Olympus Optical Co., Tokyo, Japan). Indications were various intestinal diseases. Topographical orientation was facilitated by standard positions of the instrument. The organs identified included liver, gall bladder, common bile duct, pancreas, spleen and kidneys. Pathological lesions of the organs mentioned were characterized by the echo pattern known from external ultrasonography. At present endoscopic ultrasonography is not a routine method but may provide additional information to peroral endoscopy and external ultrasonography without replacing these methods.