Ultrasoundpictures and -findings from 293 patients with 326 adrenal lesions were retrospectiv evaluated together with the medical records. 91 % of the inactive adrenal adenomas and hyperplasias (n=109) were round or ovoid, well marginated and homogeneous hypoechoic, whereas only 48 % of the adrenal metastases and lymphomas (n=124) had this findings. Pheochromocytomas (n=9) had often typical sonographic findings with complex echotexture and cystic components. Malign adrenal lesions were significant larger as benign lesions (4,8 vs. 2,7 cm; p<0,001). The logistic regression analysis in this study showed that the mass size was the most important sonographic differential sign between benign and malign adrenal lesions. A less but still significant influence had also the shape, malign lesions did more frequently show a variable shape. Lesions larger than 3,5 cm had a risk for malignancy greater than 50 %, for lesions with variable shape was this risk already over 50 % by a mass size > 2,0 cm. 25 % of the adrenal lesions in this study were incidentally discovered, so-called incidentalomas. They are most frequently inactive adenomas or hyperplasias and don't need any treatment, but it's necessary to find out the asymptomatic adrenal carcinomas, pheochromocytomas and the active adenomas among them. The abdominal ultrasound examination give important references to the diagnostic of adrenal lesions, but it isn't qualified for the differential diagnostic. Because the ultrasonography is a relative simple examination, cost-effective and without any exposure to radiation, it is especially qualified for follow up examinations of the size of adrenal masses, for example by patients with known primary carcinoma and adrenal mass. With the endosonography additional information can be obtained, especially in the left adrenal gland.