Over the past decade, our understanding of Begonia diversity in Vietnam has steadily grown, with numerous new taxa described. Most Begonia species in Vietnam exhibit highly restricted to moderately limited distributions, and many others have yet to be formally described and named. As part of our ongoing research on Vietnamese Begonia, we identified several previously unknown species within the country. After thorough morphological examination and a comprehensive review of the literature, we found that the characteristics of these specimens did not match any currently described Begonia species from Indochina, leading us to conclude that they are new to science. Here, we describe five new species: Begonia quangnamensis, B. zonata, B. thuanchauensis, B. lii and B. ducii.