A continuum based model has been used to predict liquid phase flow on sieve trays. The model uses the time and volume averaged momentum and continuity equations to predict steady state liquid velocities of froth regime flows. Vapour phase flows and the interphase interactions are specified as part of the model. Empirical correlations for distillation hydraulics are used to develop the constitutive relationships needed for closure : of the model. The model was evaluated for F-factors (defined as u(s)root rho(G) (kg (0.5)/m(0.5) s)) ranging from 0.462 to 1.464 and liquid loadings (volumetric flow per length weir) of 27 m(2)/h to 68 m(2)/h. Experimental data from Solari and Bell(1) were used to evaluate the model. On average the model is able to predict liquid velocities within 33 percent of measured values. This is a substantial improvement upon the most common assumptions and models for liquid flow on sieve trays. At low vapour loadings and high liquid loadings, the basic assumptions of the model become progressively less relevant and hence the degree of flow maldistribution is under-predicted.