 In this work, macroporous Si alloy anodes were manufactured using polystyrene (PS) spheres as a pore-forming agent. The PS spheres were easily eliminated by heat treatment, and the porosity and pore size of the electrodes were controllable by adjusting the content and size of the PS aggregates. Following heat treatment, the electrode packing density of the Si alloy anodes with 10–20 % PS decreased by 9–26 % due to removal of the PS, whereas the control electrode without PS displayed only a 1.3 % decrease. The porous electrode prepared using 10 or 15 % PS showed improved cyclic performances with capacities of 1110–1210 mAh g−1 after 100 cycles at 0.5 C. Although the macroporous Si alloy anode fabrication process using the PS beads reduced the electrode adhesion strength, the electrode performance improvements were attributed to the presence of macropores in the Si alloy electrode, which significantly reduced the changes in electrode thickness during lithiation/delithiation. The manufacture of macroporous electrodes using an appropriate PS content offers an effective strategy for applying Si-based anodes in advanced lithium ion batteries.