It is important to differentiate malignant from benign gastric ulcers (GUs) because the early detection of malignancy offers the best prognosis and is essential for planning optimal therapy. However, the differential diagnosis between a malignant and benign gastric ulcer is sometimes difficult, and remains a great challenge. Recent advances in multidetector row-computed tomography (MDCT) with three-dimensional imaging software and multiplanar reformatted (MPR) images provide a potentially powerful tool for noninvasive gastric evaluation. Virtual gastroscopy (VG) is helpful in the detection and evaluation of GU in the same way as gastroscopy. In comparison with gastroscopy, VG images can depict abnormal endoluminal lesions with a wider field of view and they have no blind point because retrospective reconstruction is available. MPR images allow the radiologist to choose the optimal imaging plane to accurately evaluate the change of the gastric wall around the gastric ulcer avoiding partial volume averaging effects. This report describes the clinical usefulness of MDCT in differentiating malignant from benign GUs by using VG and MPR images.