Despite radical surgery, the prognosis of patients who have gastric carcinoma remains unsatisfactory because of the intrinsic but unpredictable aggressiveness of this malignancy. During the past decade an ever-growing list of molecular prognostic factors has been proposed based on the discovery of the mechanisms underlying gastric cancer aggressiveness. Studies performed in larger and more homogeneous series of patients and adequate statistical analysis are warranted before any of the candidate biomarkers can be implemented in the routine clinical setting for the identification of patients at higher risk and thus for the selection of candidates for adjuvant or more aggressive therapies.