Abdominal ultrasonography in acute conditions gives sometimes the definite diagnosis or at least indicates a strategy for further examinations. This technique is constantly accurate for the upper part of the abdomen, and its classical indications are dominated by cholecystitis, biliary and urinary lithiasis, pancreatic and aortic painful circumstances. However, its role has been emphasized recently, after famous publications about the usefulness of high resolution ultrasonography for appendicitis and various gut-related acute conditions. The efficacity of abdominal ultrasonography is enhanced by color-doppler and power-doppler, to characterize some inflammatory or ischemic diseases. For the pelvis, endocavitary examination is a "must" for studying uterus and adnexae. The main drawbacks of abdominal ultrasonography are well known: its physical limitations and mainly its operator-dependence.