This paper presents a model of electro-viscosity considering effects of electric double layer on thin film lubrication with partial slip. The apparent viscosity and modified Reynolds equation are derived with consideration of electric double layer with partial slip. The apparent viscosity includes the combined effects of the electro-viscosity, the viscosity of bulk fluid and slip length. The electro-viscosity depends on the zeta potential. The effects of electric double layer with partial boundary slip on load capacity are analyzed for one-dimensional slider bearing. The electric double layer leads to an increase in apparent viscosity of lubricant and hence load capacity in thin film lubrication. Electric double layer with partial slip on parallel bearing surfaces increases the bearing load capacity. © (2014) Trans Tech Publications, Switzerland.