This is a review on the role of ultrasound for early detection and staging of cancer. In breast cancer screening ultrasound serves to clarify mammographically unclear lesions and is a primary screening tool for hereditary breast cancer. Renal neoplasms are commonly diagnosed as incidental sonographic findings and in this case are more often in a curable stage than symptomatic neoplasms. In chronic hepatitis or liver cirrhosis the annual incidence of hepatocellular cancer is more than 2% and ultrasound is used as a screening tool with 60% sensitivity and 97% specificity. According to the literature the sensitivity of native ultrasound for detecting metastases is 60% and the sensitivity of contrast-enhanced ultrasound (CEUS) is 79% or higher, i.e comparable with the sensitivity of contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI). Its role in staging is, however, limited as CT and MRI are necessary for local staging of the primary tumor and also include the liver. In the differential diagnosis of liver lesions the specificity of CEUS ranges from 82% to 99% depending on the lesion entity and is thereby comparable to contrast-enhanced CT. For staging of cervical lymph node metastases ultrasound is preferable to CT or MRI as the sensitivity lies between 79% and 90% and specificity is reported to be 90%.