Dislocations were introduced in wurtzite zinc oxide single crystals by Vickers indentations on {21 101 and {1010) surfaces at elevated temperatures, and their slip systems were determined by transmission electron microscopy combined with etch pit observations. The observed system for {21 101 indentations was 1101 11(1210) or (0001)(1210), while that for 110101 indentations was /1010/K1210). Activation of the slip systems was briefly discussed in terms of the Peierls stress and resolved shear stress acting on the slip systems. (C) 2013 Elsevier B.V. All rights reserved.