In this study, a new experimental technique, particle image shadowgraphy, is used to measure the settling velocities of spherical.particles (0.5 mm-2.0 mm) in Power-law fluids of variable viscosity and density. Different concentrations of CMC-water mixtures (0.14-0.28 wt%) are used as test fluids for the experiments. A new empirical equation, which is an improved version of the Shah et al. (2007) model; for predicting the settling velocity of a spherical particle in Power-law fluid is proposed. The new empirical model is found to give an average error of 10% in predicting the settling velocity. (C) 2016 Elsevier B.V. All rights reserved.