In this paper, the results of the experimental studies of the mixing time, as well as the power consumption and baffle presence in the stirred tank with dual eccentrically located impellers are presented. The experiments were carried out in an unbaffled flat-bottomed cylindrical vessel. Three types of impellers were used: Rushton turbine, six pitched blade turbine and six flat blade turbine. The obtained data show that eccentricity of dual impeller systems leads to reduction of mixing time. Moreover, the experimental data confirmed the enlargement of power consumption in such systems. In the paper the analysis of relation between eccentricity ratio and mixing time has been performed. (C) 2010 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.