BACKGROUND: Diabetes mellitus is a prevalent chronic disease that is becoming increasingly common worldwide and can lead to a number of dangerous complications. The Wnt signaling pathway is important for the onset and progression of diabetes. Wnt3a is a typical Wnt ligand that can increase the stability of β-catenin, control TCF7L2 expression, promote β-cell proliferation, and reduce apoptosis. SUMMARY: The involvement of the Wnt3a/β-catenin/TCF7L2 signaling pathway in the development of diabetes and associated problems related to the kidneys is reviewed in this article. KEY MESSAGE: We believe that a thorough comprehension of the molecular connections between diabetes and signaling pathways will eventually lead to improved diabetes management.