Resumo. The in vitro culture promotes changes anatomical, physiological and morphological in plants. The objective of this work was to compare the structural characteristics of leaves of Tectona grandis in in vitro culture and ex vitro. Paradermic and cross sections of the leaf blade from in vitro and ex vitro culture, hand made free, were made for the measurement of anatomical structures in the light microscope. The stomata in ex vitro culture showed smaller dimensions, while the thickness of the cuticle, the epidermal cells and parenchyma of the palisade were thicker leaves developed in ex vitro. The results indicate adaptive plasticity of T.grandis, which could allow the acclimatization of micropropagated plants under conditions of south-western Amazon.