Desiccation tolerance (DT) represents an ecophysiological strategy probably developed during land conquest by primitive plants that have been progressively lost in photosynthetic tissues throughout evolution, in parallel to the development of mechanisms for the control of water content (i.e., vascular system, cuticle, stomata). Currently, DT of photosynthetic organisms is common in algae but extremely rare in tracheophytes, especially in angiosperms. Moreover, when considering the different developmental stages of a photosynthetic organism, not all of them present the same response to desiccation. Ferns and lycophytes have three different life forms: (1) the unicellular spore – chlorophyllic or non-chlorophyllic – (2) the simple multicellular gametophyte, and (3) the complex multicellular and multi-tissular sporophyte. The three life forms comprise a wide extent of DT and particular adaptations to cope with the stresses produced by desiccation and life in the dry state. The intermediate position of ferns between bryophytes and spermatophytes in an evolutionary context, and the variation of responses to desiccation of the different life forms of ferns, allows us to use them as diverse models to study plant adaptations to terrestrial environment, as well as the evolution of the mechanisms of DT in land plants. The current knowledge on fern spore, gametophyte, and sporophyte DT and the mechanisms to survive in the dry state are reviewed in this chapter.