The present paper deals with the rheological behavior of homogeneous thickened mine tailings. Knowing the rheological behavior of a fluid is critically important and essential in the study of fluid motion, both in open channel and pressure pipe flow. The calculation of flow characteristics and parameters such as Froude number and Reynolds number are directly or indirectly related to the rheological behavior of the fluid so that the analysis of flow would not be possible without having a proper knowledge of the rheological behavior of the fluid. In order to study the rheological behavior of thickened tailings; different mine tailing slurry samples with different solid contents from three major Iranian copper mines; Sarcheshmeh, Miduk and Sungun and also the tailing samples from Peak gold mine in NSW Australia were selected. The rheological characteristics and the affecting parameters for each sample were carefully tested and determined by means of a Contraves Rheomat 155 rheometer. The solids contents of the slurry mixtures were within the range of 45% to 70% (by weight). The solid particles in the slurries had aD50 varying from 11mm to 47 mm. The particle size distribution curve for each sample was obtained using a Laser Sizer. All of the tests were performed in the technical laboratory of Rheology and Materials Processing Centre at RMIT University, Melbourne Australia. Experimental results indicated that high solid content slurry mixtures exhibit non-Newtonian behavior with shear. It reveals that these slurry mixtures should be treated and considered as a single-phase uniform and homogeneous non-Newtonian fluid. Comparison between experimental data and different theoretical models for non-Newtonian fluids motion was done and the best model fit to experimentally obtained data was recognized. Model parameters and rheological properties such as yield stress and viscosity for each slurry sample are obtained and the effect of different parameters on the Rheological properties of slurry has been investigated.