Abnormal expression of small nucleolar RNA host gene 12 (SNHG12) often changes the proliferation, autophagy, and apoptosis of cells in vivo and is significantly associated with the development and progression of tumors and some specific diseases, and therefore, it can be used as a biomarker for the screening and diagnosis of these diseases. With reference to the structure and function of SNHG12, this article elaborates on the mechanism of upregulation or downregulation of SNHG12 expression in the growth of glioma cells and the pathophysiology of ischemic stroke.