Acosta-García, G., Chapa-Oliver, A. M., Millán-Almaraz, J. R., Guevara-González, R. G., Cortez-Baheza, E., Rangel-Cano, R. M., Ramírez-Pimentel, J. G., Cruz-Hernandez, A., Gueara-Olvera, L., Aguilera-Bibian, J. E., Hernández-Salazar, M. and Torres-Pacheco, I. 2015. CaLEA 73 gene from Capsicum annuum L. enhances drought and osmotic tolerance modulating transpiration rate in transgenic Arabidopsis thaliana. Can. J. Plant Sci. 95: 227-235. Late embryogenesis abundant (LEA) proteins are an important group of proteins related to the protection of several kinds of abiotic stresses in plants. A LEA gene was cloned from Capsicum annuum seeds and named CaLEA73. This gene was expressed in C. annuum plants during several phenological stages as well as in cold stress and exogen ABA applications. The CaLEA73 gene was ectopically expressed in transgenic Arabidopsis thaliana plants in order to analyse its role under drought and salt stress. Our results displayed an increase in tolerance to drought and osmotic, but not under salt stress in the transgenic lines evaluated. Interestingly, proline levels in transgenic lines were not higher than azygous control plants, when the drought stress was evaluated. Transpiration levels in transgenic plants were lower than control, suggesting an improvement in water efficiency use in CaLEA73 transgenic lines. The stomatal density and index were significantly minor in transgenic plants in comparison to azygous control, likely indicating a reason of the minor transpiration in transgenic plants. Our results are discussed in the context of drought stress physiology aspects for crop improvement.