Biodegradable electronics open a path to new sensing applications with minimum ecological impact. In particular, biodegradable pressure sensors may enable new concepts in medical monitoring, human–machine interfaces, or tracking of industrial processes. A crucial step toward biodegradable electronics is to identify suitable and ideally bio-sourced base materials for the fabrication of substrates, conductors, and other functional layers. Here, we present a fully biodegradable pressure sensor with natural leaf skeletons as the main functional component. Leaves are used as the source material for the fabrication of the electrodes and the dielectric layers of our capacitive pressure sensors. The fabricated sensors yield sensitivities similar to state-of-the-art devices in a pressure range of about 1–50 kPa. Hence, these fully bio-degradable systems may enable applications in various areas, such as medicine, agriculture, and industrial processing.