like those ecologically sensible to the impact of hidrometheorological events. The prediction, of possible impacts of extreme events, can be favored for the comprehension of vegetation dynamics. In the present work, it was assessed the possible changes in the structure, composition and species diversity in four times (February 2017, before the impact of Irma hurricane, and after it, on February and October 2018 and April 2019), for three vegetal formations of Paredón Grande key, Ciego de Ávila, Cuba. It was recorded the number of individuals per species in 12 plots of 10 x 10 m (four plots per each plant formation). It was measured the DBH of the individuals with more than 3 cm, cover of the arboreal, shrub and herbaceous strata, foliage density and canopy height. The vegetation monitoring did not show great changes nor in the structure neither in the in the species diversity during the three analyzed years. The found changes are associated to variations in the foliage density in the higher strata of the microphyllous evergreen forest and mixed mangrove. Among the three studied vegetation types, the coastal xeromorphic thicket seems to be the one of the more resistant to the effects of Irma hurricane. The vegetation of Paredón Grande key seems to present adaptations and/or mechanism that allow its resistance and resilience to hidrometheorological severe events. Citation: Faife-Cabrera, M., Pérez-Obregón, A. & González, L. 2021. Impacto del huracán Irma en tres formaciones vegetales de cayo Paredón Grande, Ciego de Ávila, Cuba. Revista Jard. Bot. Nac. Univ. Habana 42: 93-105. Received: 15 November 2019. Accepted: 6 April 2020. Online: 3 May 2021. Editor: Luis Manuel Leyva.