Background: The Neotropical woody bamboos (NWB) comprise a clade native to the Western Hemisphere. Taxonomically the NWB are classified into three subtribes: Arthrostylidiinae, Chusqueinae, and Guaduinae. These woody bamboos are distributed from northern Mexico and the West Indies to south-central Chile and Argentina and from sea level to over 4,000 m in elevation. The most recent comprehensive treatment of the diversity and classification of NWB was published just over 20 years ago, and knowledge of the NWB has greatly increased in the interim. Questions and / or Hypotheses: How much has our knowledge of Neotropical woody bamboo diversity, distribution and classification changed in the last 20 years? Results: The present work reviews the current state of Neotropical woody bamboo taxonomy and provides 1) new morphological keys (in English and Spanish) to and synoptic descriptions of the NWB genera; 2) an updated comprehensive species list; and 3) a biodiversity analysis by country and habitat type. Neotropical woody bamboo diversity presently totals 446 species in 23 genera. In the 21st century, 103 new species and five genera of NWB have been described. Conclusions: The new species and genera described since 2000 have produced an increase in species richness of 29.5 % and a net increase in generic richness of 26.3 %. This new review will be useful for systematists, ecologists, conservation biologists and others working with woody bamboos in the Neotropics.