Herbarium collections constitute permanent and often well-documented records of the distribution of taxa through space and time. Since their creation, their uses have dramatically expanded and with many new uses being proposed, including some for which herbaria were not initially intended for. In this paper we assess the potential of these collections on conservation biology, by providing exemplary studies that use herbarium specimens, grouped into four categories: (1) based on occurrence data, such as studies about plant extinction or introduction, or those focused on modelling their ecological niche; (2) based on the specimens themselves, such as morphological or phenological studies to evaluate the impact of climate change; (3) based in genetic data, such as phylogeographic or taxonomical studies; and (4), other applied studies. Keywords: Biological collections, Conservation, Herbarium specimens, Collections databases