AbstractAimTo describe patterns in new species descriptions, examine the spatial distribution and the associated environmental conditions of the localities with newly discovered species, as well as to assess whether protected areas encompass the majority of the occurrences of undescribed species.LocationIbero‐Balear region.MethodsAfter an exhaustive literature review, the temporal and spatial patterns of the terrestrial animal species described in the Ibero‐Balear region from 1994 to 2012 were mapped. Both linear and asymptotic functions were used to compare the rates of discovered species using Akaike weights. Generalized Linear Models were used to estimate the explanatory capacity of a large set of environmental, land use and distance variables on the presence–absence of newly discovered species and on the variation in the number of new discoveries.ResultsThe average annual description rate was 112 species; 99% of the species descriptions were invertebrates. Adjusted discovery curves suggest that we still have an incomplete animal inventory. Environmental variables possess a limited capacity to predict the characteristics of the localities where new species are discovered (≈ 12%).Main conclusionsOur results indicate that it is not possible to provide an advanced estimation of the environmental and land use characteristics of the Ibero‐Balear regions in which new species will be discovered in the future. Current protected areas are not guaranteed to conserve these undiscovered species, and non‐protected areas should also be considered important reservoirs of unknown biodiversity.