Most of the available studies have been carried out in concentrations and conditions which are far removed from real waste water treatment station work conditions. The primary objective of this study is to perform systematic intrinsic viscosity measurements using two different methods on some (3) commercial anionic polyacrylamide flocculants in dilute solutions (concentration ranges from 0,002% - 0,2%). The aim of the study is to understand the behavior of the flocculants under different physico chemical conditions: temperature, electrolyte presence and a time dependent alteration of the solution’s intrinsic viscosity, according to a real wastewater treatment regime. Measurements were made using a rotational viscometer. For all the flocculants that were investigated, viscosity increases with the increase of flocculant concentration in the water (behavior that is typical for Non-Newtonian fluids). It has been determined by experiments, that an important role is played by the speed (which is different for each flocculant) at which the growth or reduction of viscosity takes place, as the viscometer cylinder changes (or increases) its’ number of rotations per minute.