Herein, the acoustically and thermally insulating epoxy foams were prepared using non-traditional expandable microspheres. The effect of foaming temperature and microsphere content on the morphology, the mechanical strength, the thermal insulation and acoustical properties of the epoxy foams was investigated in detail. It can be found that the closed pores can be partially opened by adjusting the preparation parameters, which is also accompanied by obvious changes in acoustic and thermal insulation properties. By giving high-content expandable microspheres above 2 wt%, the epoxy foams exhibit highly thermal insulation, and meanwhile achieving an acceptable mechanical property. The results convince us that such light-weight epoxy foams will outshine as the promising structural, soundproof and heat-insulated material in many multifunctional systems, such as buildings, vehicles and aircrafts. POLYM. ENG. SCI., 59:799-806, 2019. (c) 2018 Society of Plastics Engineers