Spark Plasma Sintering (SPS) has become an increasingly adopted process for hexagonal boron nitride (h-BN) manufacturing. In the SPS process, interparticle diffusion of compressed particles is rapidly achieved due to the concept of Joule heating. Compared to traditional and additive manufacturing (AM) techniques, SPS provides unique control of the structural and microstructural features of Ca components. In this study, the effect of adding calcium oxide to the spark plasma sintering of two commercial hexagonal boron nitride powders, at 1600 ºC, on microstructure, density and dielectric constant was investigated. Scanning electronic microscopy analysis of the sintered h-BN containing 5%wt of CaO samples shows most grains perpendicularly aligned to the pressure direction. Apparent density was 92.2% and 94.4% for the samples originated by h-BN powder with higher and lower initial medium particle sizes, respectively. The corresponding dielectric constant of these samples was 3 and 4.7, indicating a strong relationship of this property to microstructure and density.