Inflammatory bowel diseases (IBD) are chronic diseases of the digestive system, comprising ulcerative colitis (UC) and Crohn's disease (CD). Diagnosis is based on the endoscopic, contrast radiological and histopathological examinations. Ultrasonography is a noninvasive, repetitive, low cost imaging method and at present it is considered that its use can be a first intention examination in patients with symptoms of IBD, having the role to direct to subsequent investigations. The method has many advantages: it can evaluate the affected intestinal segment, it can indicate the structural details useful for the diagnosis such as: dehaustration, presence of inflammatory pseudopolyps and mucosal ulcerations, and the extension of the intestinal lesions. It can also give useful ultrasonographical elements which, connected to other investigations, can be used for the differential diagnosis between these two entities. Using the Doppler ultrasonography at the level of the superior and inferior mesenteric arteries and at the inflamed intestinal wall, we can assess the activity of the inflammatory process and also the evolution under treatment. Abdominal ultrasound is a complementary investigation and it cannot replace the conventional methods of diagnosis.