In this study, effect of geometrical confinement on the deformation behavior of Zr57.5Cu11.2Ni13.8Al17.5 bulk metallic glass (BMG) was investigated. For this purpose flat top conical samples with different semi-vertex angles (alpha) were prepared for quasi-static compression tests. It was observed that as the geometry of the sample is slightly changed from cylindrical shape (for which alpha = 0A degrees) to conical shape (for which alpha > 0A degrees), a brittle BMG sample tends to deform in a ductile manner due to the geometrical constraint-induced complex multi-axial stress distribution in the sample. In brittle Zr57.5Cu11.2Ni13.8Al17.5 specimen with alpha = 5A degrees, plastic deformation of about 4% was observed due to the formation of extensive intersecting shear bands.