The leaf epidermal surfaces of twenty species and one variety of Clerodendrum L., three species of Rotheca Raf. and one species of Volkameria L. were examined by peeling method and scanning electron microscope observation. Key to generaand generic descriptions of epidermal cell, trichome and stomatal complex are given. Almostall species have irregular epidermal cell with sinuous anticlinal wall. Only Volkameria specieshas isodiametric cell with straight anticlinal wall. Trichome types are not significantly different among the three genera. In addition, stomatal types can be used to classify studiedplants into two groups; anomocytic stomata occur in Clerodendrum and Volkameria, whereas diacytic stomata occur in Rotheca. The results indicate that anatomical dataprovides taxonomic supportive evidence for the three genera in Thailand.