AbstractThis work investigated the thermal properties of a new type of hollow sphere structures. For this new type, the sphere shell is perforated by several holes in order to open the inner sphere volume for a matrix material. The effective thermal conductivity of syntactic (i. e. spheres completely embedded in a matrix) perforated hollow sphere structures in a primitive cubic (PC) arrangement of unit cell models were numerically evaluated for different hole diameters, matrix volume fractions and different base materials. The results are compared to typical configurations without perforation. In the scope of this paper, three‐dimensional finite element analyses were used in order to investigate these unit cell models.