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The deep sea is a relatively stable environment, characterized by cold temperatures and poor or absent light. Relative to inshore shelf habitats, the ocean's deepwater environments remain poorly known. The continued expansion of global fishing into the deep ocean has raised new concerns about the ability of deepwater organisms to sustain the pressures of exploitation (Morato et al. 2006). General knowledge on the deep sea lags behind the expansion of fisheries (Haedrich, Merrett, and O'Dea 2001) and as such management is often further behind. The intrinsic vulnerability of the chondrichthyan fishes given their life history characteristics (Hoenig and Gruber 1990; Cahmi et a1. 1998; Musick 1999) is widely acknowledged and often cited. This vulnerability may be heightened in the deep sea, where conditions result in slower growth rates and reduced recruitment to populations. The vast majority of available life history data on the sharks, batoids, and chimaeras comes from the shallow water. Logistical, biological, and geographical difficulties with sampling (i.e., scattered distributions, deep occurrence, taxonomic uncertainty, and limited material) in the deep sea have limited the present state of knowledge. The amount of available information has, however, increased in recent years, and demonstrates that deepwater species are among the most unproductive of the chondrichthyans.Here we review the present state of knowledge concerning this diverse group of chondrichthyans, which represents some 46% of the global shark, ray, and chimaera fauna. We focus mainly on their life history, the essential information required to effectively direct management. We define the deep sea to be that region of the ocean that lies beyond the 200 m isobath, the depth generally recognized as the continental and insular shelf edge (Merrett and Haedrich 1997). Hence, deepwater chondrichthyans are those sharks, rays, and holocephalans whose distribution is confined to (or predominantly at) dept