The research which was made on 43 patients with chronic duodenum ulcer found out that iridodiagnosis is an informative method in tracing out the duodenum ulcer diseases and accessible to performed by the physicians in ambulatory conditions. The iridologic investigation emphasized the most important sings of the iris: the deformation of the autonomous ring, the pigment spots, the multiple gaps on the basis of which could be supposed or established the diagnosis of the chronical duodenum ulcer.