A colloidal deposition without any binder was developed to prepare a dense La0.8Sr0.2Ga0.85Mg0.15O3-delta (LSGM) film on porous NiO/YSZ substrates, using an incompletely crystallized LSGM powder as starting material. Both the dense LSGM film with a thickness of 15 mu m and the required phase composition of the LSGM were achieved simultaneously by sintering at 1400 degrees C for 6 h. The conductivity of the supported LSGM film attained 0.102 S/cm at 800 degrees C, which was comparable with those of the self-supported LSGM films. The maximum power density of the LSGM film cell was 480 at 800 degrees C and 614 mW/cm(2) at 850 degrees C, respectively.