Carbon nanotubes (CNTs) have attractive biochemical properties such as strong cell adhesion and protein absorption, which are very useful for a cell cultivation scaffold. In this study, we prepared a multiwalled carbon nanotube-coated collagen sponge (MWCNT-coated sponge) to improve the surface properties of the collagen sponge, and its cell culturing properties were examined. The suface of the collagen sponge was homogeneously coated with MWCNTs by dispersion. MC3T3-E1 cells were cultured on and inside the MWCNT-coated sponge. The DNA content on the MWCNT-coated sponge after 1 week of culture was significantly higher than on an uncoated collagen sponge (p < 0.05). There was no significant difference between the estimated ALP activity normalized by DNA quantity on the MWCNT-coated sponge and that on the uncoated collagen sponge which is well known as one of the best scaffolds for cell cultivation. In addition, the MWCNT-coated surface shows strong cell adhesion. Therefore, the MWCNT-coated collagen sponge is expected to be a useful 3D scaffold for cell cultivation. (c) 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009.