Gastric cancer is the final step in a multi-stage cascade triggered by long-standing inflammatory conditions (particularly Helicobacter pylori infection) resulting in atrophic gastritis and intestinal metaplasia: these lesions represent the cancerization field in which (intestinal-type) gastric cancer develops. Intraepithelial neoplasia is consistently recognized as the phenotypic bridge between atrophic/metaplastic lesions and invasive cancer. This paper addresses the epidemiology, pathology, molecular profiling, and clinical management of advanced precancerous gastric lesions.