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|YSZ|YSZ-LSM|LSM. After sintering, the electrolyte and YSZ-LSM electrode were 9 and 20 μm thick, respectively. The performances of these reactors were determined as fuel cells, operating with dry H2, and as electrolysers, operating with CO/CO2 in the ratio 1/9. At 788 °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.