A layered polysilicate material, Na-magadiite, and its organically modified derivative, dodecyltrimethylammonium-magadiite (C12TMA-magadiite) were studied for the immobilization of cytochrome c. The protein readily adsorbs onto the solids from a buffered solution under mild conditions (pH = 7.2, ambient temperature). The amounts of adsorbed cytochrome c were determined by UV-visible spectroscopy analysis of the supernatant solutions. The spectral features of the immobilized cytochrome c are similar to those of the free protein, indicating no alteration of protein structure. However, the binding interactions appear to depend on the nature of the solids. Cytochrome c was found to leach off the C12TMA-magadiite material under certain buffer and time conditions, while no leaching was observed under identical conditions in the case of Na-magadiite. We confirmed that cytochrome c displaces the C12TMA+ ions originally present between the layers. X-ray diffraction results are consistent with cytochrome c intercalation into C12TMA-magadiite but not into Na-magadiite. Preliminary evaluation of the activity of the immobilized cytochrome c was also conducted.