Add to ORKGTextile Reinforced Mortar (TRM) composite systems are among the most promising techniques for strengthening masonry elements. This study aims to assess the mechanical performance of a sustainable TRM system internally reinforced by natural fabric. More specifically, specimens consisting of a bi-directional flax fabric and a hydraulic lime-based mortar were subjected to tensile tests. The TRM under consideration showed a behaviour not significantly different from the one typically exhibited by similar materials reinforced by non-plant fibres. Moreover, the so-called exploitation ratio of the internal textile remained almost unchanged in TRM systems with either one and two layers of fabric. These aspects confirm the potential of using plant f...