In this work, the terminal failing velocities of a series of cylinders made of four different materials and encompassing length-to-diameter ratios varying from similar to 0.5 to 10 hale been measured in well-characterized non-Newtonian solutions. Five aqueous polymer solutions exhibiting varying levels of shear-thinning and viscoelasticity have been used as model test fluids. Experimental results for freely falling cylinders ale expressed in terms of a correction factor to be applied to the Stokes formula when the particle Reynolds number is small ( < 1). This correction factor can be decomposed into two component; namely, one for the shape and the other fur the non-Newtonian characteristics of the liquid. While an existing correction for non-spherical shape seems to work; well, a new correlation is presented to account for the role of shear-thinning and viscoelastic characteristics. Within the range of conditions covered in this work, the terminal falling velocity is influenced primarily by shear dependent viscosity. <(c)> 2001 Elsevier Science Ltd. All rights reserved.