Mango pulp was treated with pectinase enzyme at different times (30-150 min) and temperatures (25-60 degrees C) of treatment, and at various concentrations of enzyme (0.005-0.095%). The effect of these enzyme treatment conditions on the rheological parameters (yield stress, flow behaviour index and consistency index) and the apparent viscosity were determined employing a second order central composite rotatable design in combination with response surface methodology. The raw, as well as the enzyme-treated mango pulp behaved as pseudoplastic liquid and possessed yield stress. The Herschel-Bulkley model fits well (r greater than or equal to 0.991, p less than or equal to 0.01) the shear rate and shear stress data. An increase in time and/or concentration of enzyme treatment is associated with art increase in the flow behaviour index. Apparent viscosity markedly decreased with an elevation in the concentration of the enzyme.