The incidence of oesophageal cancer has been rising for the past decades in the western world due to the rapid increase of oesophageal adenocarcinoma. Strategy and extent of the diagnostic work up in case of suspected oesophageal cancer should be focussed on the therapeutic consequences which have to be drawn in the individual patient. Upper endoscopy including biopsy will provide the diagnosis and the location of the tumour, computed tomography and transcutaneous sonography are used to rule out distant metastases. Endoscopic ultrasound is the tool of choice to obtain an exact locoregional staging - an experienced investigator may correctly classify the tumour according to the T-N-categories in about 80% of the cases. To define early cancers restricted to the mucosa, which may be suitable for local ablative therapy, high-resolution endosonography is essential. Intravital staining methods may help to delineate flat or multifocal cancers, they are also used to better recognise dysplastic foci in a Barrett-segment. To rule out osseous metastases a bone scintigraphy is indicated. In tumours located proximal to the bifurcation a bronchoscopy completes the diagnostic procedures, in case of advanced tumours of the oesophagogastric junction laparoscopy may be performed to rule out peritoneal carcinosis.