The study of stem (i.e., xylem and bark) anatomy has a long tradition in forestry and wood science. Traditionally, stem anatomical properties have been studied mainly for commercial or taxonomic purposes. Yet, with the emergence of trait-based ecology in the last decades, there has also been an increasing interest in studying stem anatomy from an ecological perspective. Stem anatomical structure plays a key role in plant functioning; thus, it may provide valuable insights into various ecological questions. Recent evidence indicates that stem anatomy may be particularly relevant to address questions on plant functions, species demography and community assembly. Addressing these questions would be especially important for tropical forests, as our knowledge on the diversity of xylem anatomical structures of tropical forest plants, and its ecological significance, is still limited. In this symposium, we will bring a diverse group of speakers to explore and discuss how xylem anatomical traits are related to woody plant functioning and performance. The symposium will offer a broad range of perspectives and approaches, including different plant organs (i.e., xylem, bark) and spanning various environments within the tropics. It will ultimately provide critical insights to better understand the multiple ways in which stem anatomy can shape plant functioning and forest dynamics across the tropics.