In this paper, experimental data on the mixing time of the continuous phase and power consumption of gas-liquid-liquid dispersions in a mechanically agitated baffled tank are presented. The electrical conductivity method is taken for the measurement of mixing time and the shaft-torque method for power consumption measurement. Tap water is used as the continuous phase, and kerosene and air as the dispersed ones. The effects of probe/tracer injection position, agitation speed, type of impeller, clearance of impeller off tank bottom, oil volume fraction, gas holdup and physical properties of the dispersed liquids on the macro-mixing of the gas-liquid-liquid system have been investigated. The phenomenon of gas-liquid-liquid macro-mixing in a stirred tank is largely similar to that of liquid-liquid and gas-liquid stirred tanks. Our experiments indicate that the gas-liquid-liquid macro-mixing can be enhanced at higher gas holdups while damped at low gas holdups. Contrary to gas effect, the dispersed oil phase at low holdups increases the macro-mixing intensity but at higher holdups decreases the macro-mixing intensity of the continuous phase. The experimental results show that axial impellers are more energy efficient for gas-liquid-liquid macro-mixing than radial impellers. A simple correlation is developed for predicting the mixing time in gas-liquid-liquid three-phase systems and satisfactory agreement with experimental data is observed. (C) 2012 Elsevier Ltd. All rights reserved.