Abstract: Leaf epidermal investigations were carried out on three species of Mimosa, M. pudica, M. invisa and M. pigra common in Nigeria. The results obtained revealed the nature of the irregularly shaped epidermal cell walls of M. pigra and M. pudica. The epidermal cell walls of M. invisa were however mostly rectangular to pentagonal in shape. Morphological type of stomata was the diacytic type in all the species. The average stomatal index of 13.43% on the upper epidermis of M. invisa and that of 40.91% on the lower epidermis was significantly different from the stomatal index of the other two species. The result of this investigation will help in the taxonomy and also contribute to more information on the biology of these three obnoxious species of Mimosa.