A new equation for the relative viscosity of infinitely dilute emulsions of noncolloidal droplets is proposed using the analogy between shear modulus and shear viscosity. In the limit of capillary number --> 0, the proposed equation reduces to the well-known Taylor viscosity law for infinitely dilute emulsions. Starting from the proposed equation for an infinitely dilute emulsion, new viscosity equations for concentrated emulsions are then developed using a differential scheme. The proposed equations for concentrated emulsions are evaluated in light of a large body of published experimental data on the viscosity of emulsions. (C) 2003 Published by Elsevier Science (USA).