Preliminary results are presented on the phase behavior and the effects of a weak external electric field on ternary mixtures composed of soybean lecithin, n-decane, and small amounts of water. At a water content in the range 1 to 2.1 water molecules per lecithin molecule, a highly-viscous homogeneous organogel, previously described by Luisi et at, has been obtained. The voltage applied has induced a phase separation and a significant decrease in the solution viscosity. These effects are possibly due to an orientation of tubular reverse micelles in respect to the electric field lines, decreasing their entanglement coupling. At a water content exceeding 2 molecules per lecithin molecule, two-phase systems have been formed which consisted of a low-viscous solution and compact gel or solid precipitate. In the latter case the electric field first has brought about the typical electrorheological response, i.e., increased viscosity. On further processing, a sharp drop in the viscosity has been observed. Optical examination has shown that under the action of an external electric field the solid particles assembled into columns have experienced phase transformations initially into transparent birefringent mesophase and finally into optically isotropic mass.