The coefficient of compressibility, k = Delta V/V-o, of {water (1) + tert-butanol (2)} binary mixture was measured at pressures from 0.1 to 100 MPa and temperatures from 278.15 to 323.15 K over the concentration range of liquid mixture occurrence. The whole composition range from 0 to 1 tert-butanol mole fraction was studied at 323.15 K only because of the mixture freezing at lower temperatures. Over the whole pressure range in question partial molar volumes of the components at all temperatures studied and excess molar volumes of the mixture only at 323.15 K were calculated. It was shown that when pressure increased, the values of excess molar volume decreased, and minimum on concentration dependence of V-E on tert-butanol mole fraction shifted to the region of low tert-butanol content. For every pressure studied extremes were observed on the concentration dependences of partial molar volumes of the mixture components. The values of limiting partial molar volumes increased with temperature growth and tended to maximum at pressure slightly higher of 100 MPa. (C) 2012 Elsevier Ltd. All rights reserved.