Porous Si3N4/BN ceramics were prepared via nitridation of silicon powder, with Si and BN as starting powder, Y2O3as sintering additive. After nitridation and sintering at 1680°C, porous Si3N4/BN ceramics with a porosity of 47%–51% and a flexural strength of 170–90 MPa were obtained. Compared with pure porous Si3N4ceramics, the grains of porous Si3N4/BN ceramics were finer, the aspect ratio of β‐Si3N4grains was higher, and the pore size was decreased, which can be attributed to grain‐boundary pinning due to BN dispersions. The relatively high flexural strength was obtained with 5% BN addition. The porous Si3N4/BN ceramics also showed low shrinkage and machinable properties.