In this paper the available data for the measurement of viscosity of aluminium and its alloys are reviewed. Most measurements are performed with an oscillating vessel technique and the merits of this technique are discussed. The purity of the aluminium affects the measured viscosity values and we recommend a value of between 1.0-1.4 mPa(.)s for the pure element at the melting point. Although studies of the viscosity of aluminium alloys are limited, the effects of elemental additions to the alloy are similar to those for additions to the base metal. Thus an increase in concentration of Ti, Ni, Cr, Mn, Mg tends to increase the viscosity whereas the viscosity decreases with increasing Zn and Si concentrations. Also purification of an alloy decreases the viscosity. There is a wide variety of models ranging from those based on empiricism to thermodynamic methods. With the present quality of input data it is probably better to use a simple rather than a sophisticated model. (C) 2004 Kluwer Academic Publishers.