The thermally reversible gel phases can be representative, on a visual scale, of the ‘‘soft state’’ of matter. The fibrillar structures found in aqueous biological systems (gels of microtubules, collagen, chitin, actin) can also been observed in organic media. We study the physical gel networks made up with non macromolecular surfactants in organic media. Considering a few examples of binary systems (gelator+solvent), we can survey a large variety of behaviors. The molecular organization within the fibres and the aggregation mechanisms are discussed. Structures appear to be function of the stericity of the gelator, its polarity, its chirality, its chemical functionality and can also be solvent and concentration dependent. Small angle neutron scattering and electron microscopy are some of the complementary techniques used.