The objective of this study was to verify the possible changes in leaf anatomy and photosynthetic char-acteristics of ‘Mac¸ ã’ (Silk) banana plantlets cultivated in vitro in the presence of different silicon sources.‘Mac¸ ã’ (Silk) banana plantlets pre-established in vitro were transferred to MS medium containing 30 g L−1sucrose, 1 mg L−1NAA and 1.8 g L−1PhytagelTMand 1.0 g L−1of three different sources of silicon: Na2SiO3,K2SiO3and CaSiO3. The control group was conduced without silicon addition. After 45 days, gas exchangeswere measured in infrared gas analyser and the leaf anatomy and chlorophyll content were evaluated aswell as the silicon content in plants. The presence of calcium and sodium silicates enabled higher levelsof silicon in the leaves than in the roots, however, potassium silicate promoted higher levels of siliconin the roots. Plantlets grown in the presence of calcium silicate had a higher photosynthetic rate andchlorophylls content compared to other treatments. There was a thickening of the epidermis, increasedstomatal density, thicker mesophyll, thicker palisade parenchyma and a higher proportion of palisadeparenchyma in relation to spongy parenchyma in seedlings grown in the presence of calcium silicate thanin the control and other treatments. Silicon promoted more functional features and greater adaptabilityof ‘Mac¸ ã’ (Silk) banana plantlets, and the calcium silicate is a more efficient source for the promotion offavorable features in the in vitro culture of this species