Cobaltabisdicarbollide derivatives have been anchored for the first time to the surface of TiO2 particles using two phosphorus-containing cobaltabisdicarbollide derivatives: Cs[1,1'-mu-(HO)(O)P-3,3'-Co(1,2-C2B9H10)(2)], Cs[1], and Cs[8,8'-mu-(OH)(O)-P(O)(2)-3,3'-Co(1,2-C2B9H10),](2) Cs[2]. Grafting of cobaltabisdicarbollide anions to the TiO2 particle surface through phosphinate or phosphate anchors has been achieved by using standard conditions. Characterization of the modified titanium dioxide surfaces by FTIR, B-11 and P-31 NMR, DRUV-vis spectroscopy, and transmission electron microscopy (TEM) indicates an efficient functionalization on the particle surface.