Nonporous elastomeric particles are often employed to improve the toughness of brittle epoxy foams but this also decreases their compressive strength and stiffness. Herein, a novel strategy utilizing hollow elastomeric microspheres as toughening agent for epoxy foams is presented. The addition of 0.5 wt.% hollow elastomeric microspheres into epoxy foam leads to a 15% increase in critical stress intensity factor (K1c) to 0.38 MPa m0.5and 33% increase in Charpy impact strength (acU) to 1.05 kJ m−2, respectively, compared to unfilled epoxy foam (K1c = 0.33 MPa m0.5and acU= 0.79 kJ m−2). However, a further increase in the hollow elastomeric microsphere concentration to 1.0 wt.% leads to microsphere agglomeration, which reduces both K1cand acUto 0.35 MPa m0.5and 0.93 kJ m−2, respectively. Nevertheless, the added hollow elastomeric microspheres do not lead to a reduction in the quasi-static compressive properties of the epoxy foams.