Adenocarcinomas and neuroendocrine neoplasms (NEN) and lymphomas are the most frequent malignant small bowel tumours in the Western World. In Asia, gastrointestinal stromal tumours (GIST) are observed more often than those in Western countries. Rarely, sarcomas other than GIST are detected in the small bowel. Metastases to the SB are rare, among them malignant melanoma is a frequent cause. Typically, GIST and NEN present as subepithelial tumours, while carcinoma often manifests as ulcerated mass lesions. Endoscopic appearance of SB lymphomas is variable, often mimicking other diseases. Small bowel capsule endoscopy (SBCE) is not able to reliably differentiate between different entities. Diagnosis of small bowel tumour is frequently made by SBCE during work-up of suspected small bowel bleeding. However, device-assisted enteroscopy (DAE) is the preferred method in patients with obstruction or suspected tumour at cross-sectional imaging. DAE allows for obtaining biopsies for histologic diagnosis and marking the localization with a tatoo prior to surgery. Often a combination of SBCE, DAE, and imaging is necessary for diagnosis.