Abstract In this study, we developed a hydrostatic pressurizing chamber capable of applying hydrostatic pressure to osteocytic spheroids derived from mouse osteoblastic MC3T3-E1 cells. Our results demonstrate that a 4-hour exposure to 200 kPa of hydrostatic pressure did not alter the apparent morphology of the spheroids. However, gene expression analysis revealed a significant up-regulation of Sost, marker of late-stage osteocyte differentiation.