This taxonomic survey of Dendrobium section Formosae in the flora of Cambodia, Laos and Vietnam includes 19 species (Dendrobium bellatulum Rolfe, D. cariniferum Rchb.f., D. chapaense Aver., D. christyanum Rchb.f., D. daklakense Tich, Schuit. & J.J. Verm., D. draconis Rchb.f., D. infundibulum Lindl., D. kontumense Gagnep., D. longicornu Lindl., D. multilineatum, D. ochraceum De Wild., D. roseiodorum Sathap., T.Yukawa & Seelanan, D. scabrilingue Lindl., D. senile E.C.Parish & Rchb.f., D. suzukii T.Yukawa, D. trankimianum T.Yukawa, D. trigonopus Rchb.f., D. wattii (Hook.f.) Rchb.f., D. williamsonii Day & Rchb.f.) hitherto recorded from these countries. It includes a key for species identification and updated information on species nomenclature, morphology, phenology, ecology, distribution and tentative conservation status.