Electrochemical micromachining (ECMM) with ultrashort voltage pulses has been used to fabricate microstructures on a NiTi shape memory alloy (SMA). Because of its unique properties, NiTi is a desirable material for use in various applications including medical devices and actuators. ECMM is a heat-free, strain-free, and mask-free method for microfabrication, and therefore well suited for use with shape memory alloys. Microstructures were machined to a depth of 3 mu m on NiTi surfaces, and the lateral resolution of the machining was found to be dependent on the duration of the voltage pulses used. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.002202esl] All rights reserved.