Inkjet printing is an economical additive manufacturing technique with minimal material waste, which offers a high degree of control over vertical resolution, so lending itself well to the fabrication of the functional layers of solid oxide electrochemical reactors. We formulated a printable and stable colloidal dispersion of La0.8Sr0.2MnO3 (LSM) - (Y2O3)(0.08)(ZrO2)(0.92) (YSZ) ink to print sequentially onto an inkjet-printed YSZ electrolyte sintered to a Ni-YSZ substrate to form the cell: Ni-YSZ vertical bar YSZ vertical bar YSZ-LSM vertical bar LSM. After sintering, the electrolyte and YSZ-LSM electrode were 9 and 20 mm thick, respectively. The performances of these reactors were determined as fuel cells, operating with dry H-2, and as electrolysers, operating with CO/CO2 in the ratio 1/9. At 788 degrees C, the peak fuel cell power density was 0.69 W cm(-2), and at a cell potential difference of 1.5 V, the electrolysis current density was 3.3 A cm(-2), indicating that the performance of inkjet-printed YSZ-LSM electrodes can exceed those fabricated by conventional powder mixing processes. (c) 2018 The Authors. Published by Elsevier Ltd.