Mixing is an essential part of chemical processes. In the present work, homogeneous mixing at relatively high throughput for a single microchannel (of 1-18 mL/min) was investigated in microchannels with different dimensions, cross sections and mixing elements (with and without structured internal surface). A method based on the Villermaux-Dushman reaction was employed and the intensity of segregation was determined. Further, simulations were carried out to investigate the mixing time and the effectiveness of different microchannels. The data obtained for mixing time was correlated in terms of specific power dissipation which can be used for a priori predictions of mixing in microchannels. The results show that a microchannel with structured internal surface shows better performance in terms of mixing efficiency which has to be paid by high energy consumption. (C) 2010 Elsevier B.V. All rights reserved.