The relative influence of some polyhydric alcohols, differing in their molecular weight, degree of dissociation and complex forming capacities, on the flow behaviour of bentonite suspension has been studied at room temperature. The experiments were conducted in non-Newtonian region and as such rotational cup and bob viscometer of Mc-Michael type was used. The changes in particle interaction and modes of particle association have been evaluated through the measurement of rheological properties such as yield stress and plastic viscosity of the interacted suspension. A significant reduction of plastic viscosity was noticed in all cases with the increase in yield value. © 1999 Taylor and Francis Group, LLC.