The steady shear viscosity, dynamic viscoelasticity, and high shear wave rigidity modulus were measured for silica dispersions stabilized by a nonionic surfactant, dodecyl hexa ethylene glycol monoether (C12E6). Electrokinetic measurements were also obtained to help understand the role of charge on the stability of the silica particles in nonaqueous media. The dispersions were found to be stable at low levels of C12E6 concentrations due to electrostatic repulsions as deduced from zeta potential data. Zeta potentials of silica particles in mono ethylene glycol (MEG) were of the order of (-)20-(-)70 mV, signifying the importance of electrostatic stabilization normally reported in aqueous media. Instability oil further addition of C12E6 to silica particles in MEG, a phenomenon normally obtained with high molecular weight polymers, is explained in terms, of micellar bridging and hydrophobic interactions. The extended Derjaguin-Landau-Verwey-Overbeek (DLVO) theory is used to model the effect of C12E6 on particle stability. Viscoelasticity of silica in MEG in the presence of C12E6 is also reported. Viscoelasticity was found to be due to weak flocculation resulting in a free energy increase and a decrease in configurational entropy as the dispersion was weakly strained. Viscoelastic measurements are modeled using a mode-coupling model.