Bulk metallic glasses (BMGs), with its unique amorphous microstructure, have been increasingly used in various applications such as optical molds, aerospace and biomedical components. Micro milling can be used to fabricate BMGs with very high geometric accuracy and surface quality. However, amorphous to crystalline transition could occur during micro milling BMGs, which significantly affects the surface integrity of the produced components. This present work quantifies the extent to which the amorphous to crystalline phase transition will occur during micro milling of zirconium based BMG (i.e. LM105). This can then be used to optimize the cutting conditions and prevent the phase transition from commencing. The subsequent result is an increase in surface quality and machining efficiency during BMGs components fabrication.