Permeabilization of the mitochondrial outer membrane by the executioner proteins of the BCL2 family BAX and BAK is a key step in the regulation of apoptosis. Despite intense research, we still fail to understand the structural organization and dynamics of assembly of the apoptotic pore formed by these proteins. Here, I will present the direct visualization of BAX and BAK macromolecular assemblies on the mitochondria of apoptotic cells using super-resolution microscopy, as well as the quantitative comparison on their oligomerization during pore growth. A multi-correlative microscopy approach allows for the first time to correlate the stoichiometry of BAX and BAK molecules, with their supramolecular organization and the opening of membrane pores at mitochondria.