Transforming growth factor-beta 2 (TGF-beta 2), an important member of the TGF-beta family, is a secreted protein that is involved in many biological processes, such as cell growth, proliferation, migration, and differentiation. TGF-beta 2 had been thought to be functionally identical to TGF-beta 1; however, an increasing number of recent studies uncovered the distinctive features of TGF-beta 2 in terms of its expression, activation, and biological functions. Mice deficient in TGF-beta 2 showed remarkable developmental abnormalities in multiple organs, especially the cardiovascular system. Dysregulation of TGF-beta 2 signalling was associated with tumorigenesis, eye diseases, cardiovascular diseases, immune disorders, as well as motor system diseases. Here, we provide a comprehensive review of the research progress in TGF-beta 2 to support further research on TGF-beta 2.