The fabrication of stretchable electronic devices is presently rather challenging on account of both the limited number of materials showing the desired combination of mechanical and electrical properties and the lack of techniques to process and pattern them. Here we report on a fast and reliable transfer patterning process to fabricate high-resolution metal microelectrodes on polydimethylsiloxane (PDMS) by using ultrathin Parylene films (2 μm thick). By combining transfer patterning of metal electrodes with orthogonal patterning of the conducting polymer poly­(3,4-ethylenedioxythiophene) doped with polystyrenesulfonate (PEDOT:PSS) on a prestretched PDMS substrate and a biocompatible “cut and paste” hydrogel, we demonstrated a fully stretchable organic electrochemical transistor, relevant for wearable electronics, biosensors, and surface electrodes to monitor body conditions.