Objective To investigate the effects of the androgen receptor (AR) inhibitor flutamide on the proliferation, apoptosis, and invasion of human glioma cells in vitro, since AR is overexpressed in glioma tissues and is a risk factor for the development and progression of gliomas.Methods Different concentrations of flutamide (1.0×10^-8, 1.0×10^-7, and 1.0×10^-6 mol/L) were added to glioma U251 cells. The mRNA and protein expression of AR was measured by real-time PCR and Western blot, respectively. Cell Counting Kit-8 assay was used to investigate the effect of flutamide on glioma cell proliferation. Flutamide-induced apoptosis of glioma cells was detected by Annexin V-7AAD/PE staining. The change in glioma cell invasion in the presence of flutamide was evaluated by Transwell assay.Results Flutamide significantly inhibited the proliferation and invasion and increased the apoptosis of U251 cells in vitro, in a dose-dependent manner.Conclusions The AR inhibitor flutamide can significantly inhibit the proliferation and invasion of glioma cells and induce their apoptosis in vitro, and AR may be a risk factor for the development and progression of gliomas.