Due to their brittleness, bulk metallic glasses (BMG) are generally difficult to form at room temperature. A fruitful way to get components is to deform them in their supercooled liquid region (SLR). In this region, BMG generally exhibit particularly large strain capacities. This behaviour is sometimes reported as superplasticity since several requirements of superplasticity are fulfilled. For instance, particularly large m values (up to 1) can be measured and consequently one can wonder if such forming conditions of BMG can be considered as ideal superplasticity. In this paper, we report studies dealing with high temperature deformation of various BMGs. Similarities and differences between high temperature deformation of BMGs and superplasticity of fine grained alloys are discussed.