Pollen morphology of 13 genera and 26 species of Urticaceae in Thailand were investigated in order to examine the taxonomic significance of the pollen morphological characters for this family. The pollen grains were acetolyzed and investigated under the light and scanning electron microscopes. The results show that the general pollen characters of Urticaceae are monad and radially symmetrical. The size of pollen grains is small (10–16 μm) or minute (7–9 μm). The pollen types are 2–3-porategrains, pore with or without annulus. The pollen shape isoblate spheroidal, suboblate, prolate spheroidal and subprolate. The exine sculpturing are granulate, microbaculate, microechinate and microverrucatemicroechinate. The presence of annulus around the pore is the diagnostic character of the Elatostema group (Elatostema, Pellionia and Procris).The pollen morphological characters can be used for the identifi cation of only some genera of Thai Urticaceae and are helpful for distinguishing some species. Thus, the taxonomic implication of pollen morphology for Urticaceae is limited.