The aim of this study is to investigate the mechanical properties of sunflower stems. Sunflower stems have two parts: the bark and the pith. Since the mechanical properties of the bark and those of the pith are different, separate mechanical tests were performed. The influence of both the moisture content and of the location of the specimens along the stem was studied. An increase of moisture content of bark and pith was found to reduce their Young’s modulus. The Young’s modulus increases with the location of the specimen along the stem.