The application of the gelling properties of some polysaccharides in the consolidation of ceramics (gel casting) allows the forming of dense complex-shape samples through colloidal routes. A description of those polysaccharides, their gelling mechanisms (chemical and thermal), and their synergistic interaction with non gelling polysaccharides is revised, as well as their application in the shaping of 3D (bulk) and 2D (substrates, coatings, and laminates) ceramics. The materials obtained by this methodology show both homogeneous microstructures and high green mechanical strengths, which make possible the machining in the green state, with the corresponding costs reduction.