C-Glycosides are critical, naturally occurring products and medicinal candidates, and extensive efforts have been made to explore efficient approaches for creating C-glycosidic bonds. Transition-metal-catalysis, particularly nickel-catalyzed C-glycosylation reactions constitute a promising strategy. However, achieving a stereoselective synthesis of α- and β-C-glycosides has been a long-standing challenge. To address this problem, a variety of nickel-mediated strategies have been developed. This review highlights recent developments in the nickel-catalyzed diastereoselective C-glycosylation reactions and briefly summarizes the mechanistic understandings of these methods.