Reducing　the　size　of　metallic　glasses　(MG)　to　submicron　or　nanoscale　levels　improves　their　strength　and　ductility.　However,　there　is　no　clear　consensus　in　the　literature　regarding　their　mechanical　behavior　in　the　presence　of　a　flaw　or　notch.　In　this　work,　quantitative　tensile　tests　on　notched　submicron　sized　CuZr　MG　specimens　were　conducted　inside　a　transmission　electron　microscope　to　study　their　deformation　characteristics.　Strength　was　found　to　be　notch　insensitive　for　shallow　notched　thick　specimens,　although　reducing　specimen　dimensions　and　increasing　notch　sharpness　enhances　it　by　14%.　It　was　reasoned　that　the　severity　with　which　shear　bands　are　geometrically　constrained　determines　the　strength　and　fracture　morphology　of　notched　specimens.　Softening,　accompanied　with　a　transition　to　necking　failure,　occurs　when　the　width　of　ligament　that　connects　the　notches　is　smaller　than　80　nm.　The　competition　between　shear　band　propagation　and　plastic　zone　growth-mediated　homogeneous　activation　of　shear　transformation　zones　was　found　to　be　responsible　for　this　brittle　to　ductile　transition.　Current　results　provide　unique　insights　into　the　various　design　aspects　to　be　considered　for　reliable　engineering　of　small　scale　components.　(C)　2018　Acta　Materialia　Inc.　Published　by　Elsevier　Ltd.　All　rights　reserved.