Preoperative diagnosis and staging of primary gastrointestinal (GI) neoplasms are challenges for both clinicians and radiologists. Barium studies are very sensitive in disclosing primary malignancies, even at an early stage. Radiologic signs depend on the evolutional stage of the disease and its appearance on gross pathology. A neoplasm may be manifested on barium studies by a wide spectrum of findings, including mucosal abnormalities, mass presence, ulcerative lesions, submucosal infiltration, and lumen stenosis. Advanced disease can be accurately diagnosed, whereas early cancer should be differentiated from other neoplastic or inflammatory disorders by meticulous analysis of radiologic findings. The extent of GI involvement and multiplicity of the lesions can be assessed on barium studies. In the staging of GI neoplasms, barium studies are of little value. Skeletal survey by conventional radiographs and chest plain films can reveal distant metastases in a short time and with low cost, although they are not that sensitive to the detection of early or subtle lesions. The exact role of conventional radiology in the imaging workup of GI malignancies depends on local expertise and availability of other diagnostic techniques and modalities.