Objective Glioblastoma multiforme (GBM) is the most prevalent and aggressive primary cerebral tumor. The median survival time is 15 months despite maximum treatment because the tumor is resistant to most therapeutic modalities. Several studies have indicated chemopreventive and chemotherapeutic activity of cyanidin-3-glucoside (C3G) as an anthocyanin component. We aimed to illustrate the cytotoxic and apoptogenic effects of C3G in the U87 cell line (human GBM cell line). Methods Cytotoxic activity was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tetrazolium assay after treatment with C3G at different concentrations in the U87 cell line. Cisplatin was used as a positive control for 24 and 48 hours. The percentage of apoptotic cells was determined using an Annexin V/propidium iodide assay, and the expression of bax, bcl2, and p53 genes was assessed using real-time polymerase chain reaction. Results Treatment of U87 cells with 40 μg/mL of C3G resulted in 32% apoptotic cells after 24 hours. To further confirm that C3G treatment induced apoptosis in U87 cells, RNA expression of bax, bcl2, and p53 genes was investigated after treatment. Real-time polymerase chain reaction indicated that the expression of bax and p53 increased, whereas the expression of bcl2 decreased. Conclusions C3G had an apoptogenic effect in the GBM cell line. New information regarding the therapeutic effects of C3G in GBM could ultimately lead to the production of new drugs.