The aim of the study is to estimate the effects of the water-holding capability of the polyvinyl formal (PVF) sponges on osteogenic response in vitro experiments. The rat bone marrow stem cells (BMCs) were seeded and cultured for up to 4 weeks under static conditions in osteogenic media to evaluate the adhesion, proliferation, differentiation, and mineralization on the Dextran-coated PVF sponges with or without water-holding capability. The BMCs seeded onto the PVF sponges with water-holding capability showed more significant increases in DNA content, alkaline phosphatase (ALP) activity, osteocalcin content, and calcium deposition than those without water-holding capability. These results suggest that the Dextran-coated PVF sponges with high water-holding capability would have potential uses as both a new scaffold to bone tissue engineering and as a new biomaterial. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 247–253, 2014.