<p><i>In operando</i> NMR spectroscopy is a method for the online investigation of electrochemical systems and reactions. It allows a real-time observation of the formation of products and intermediates, and it grants insight into the interactions of substrate and catalyst. An <i>in operando</i> NMR setup for the investigation of the electrolytic reduction of CO<sub>2</sub> on silver electrodes has been developed. The electrolysis cell consists of a three-electrode setup using a working electrode of pristine silver, a chlorinated silver wire as reference electrode, and a graphite counter electrode. The setup can be adjusted for the use of different electrode materials and fits inside a 5 mm NMR tube, Additionally, a shielding setup was employed to minimize noise caused by interference of external radio frequency (RF) waves with the conductive components of the setup. The electrochemical performance of the <i>in operando</i> electrolysis setup was investigated in comparison to a standard CO<sub>2</sub> electrolysis cell. The small cell geometry impedes the release of gaseous products, and thus it is primarily suited for current densities below 1 mA/cm<sup>2</sup>. The effect of conductive components on <sup>13</sup>C NMR experiments was studied using a CO<sub>2</sub> saturated solution of aqueous bicarbonate electrolyte. Despite the <i>B</i><sub>0</sub> field distortions caused by the electrodes, line widths of <i>ca.</i> 1 Hz could be achieved. This enables the investigation of interactions in the sub-Hertz range by NMR spectroscopy. It was found that the dynamics of the bicarbonate electrolyte change due to interaction with the electrochemical setup, by catalyzing the exchange reaction between CO<sub>2</sub> and HCO<sub>3</sub><sup>−</sup> and affecting the formation of an electrical double layer.</p>