The use of stable isotopes as ecological tracers in deep-sea ecosystems has a long history, dating back to the late 1970’s. Stable isotopes have been instrumental to many key-findings about ecosystem functioning, particularly in chemosynthesis-based habitats (hydrothermal vents, cold seeps). However, constraining sampling logistics commonly limit the scope, extent, and therefore insights drawn from isotope-based deep-sea studies. Overall, much is left to discover about factors globally influencing food web structure in deep-sea ecosystems. In this context, deep-sea ecologists have to ensure that no sample is left unexploited, and that all generated data are easily discoverable, available and reusable. DeepIso is a collaborative effort to produce a global compilation of stable isotope ratios and elemental contents in organisms from deep-sea ecosystems. In doing so, it aims to provide the deep-sea community with an open data analysis tool that can be used in the context of future ecological research, and to help deep-sea researchers to use stable isotope markers at their full efficiency. More info about the project can be found at https://loicnmichel.com/deepiso/ As of v2 (2021/08/12), the database contains 18 distinct datasets, for a total of 38335 fully documented measurements. Archived parameters currently include δ13C (n = 7690), δ15N (n = 7491), δ34S (n = 3266), %C (n = 5753), %N (n = 5614), %S (n = 3342) and C/N ratio (n = 5719). Those measurements pertain to 7248 distinct samples belonging to 881 taxa, plus sediments, suspended particulate organic matter, plankton, and detritus. Samples were taken between 1989 and 2018 in multiple environments (hydrothermal vents, cold seeps, cold water coral reefs, and other benthic or pelagic environments) and at depths ranging up to 5338 meters. The database consists of two files: one containing the data itself, and one describing all used terms (measurements or metadata, derived from Darwin Core standards, https://dwc.tdwg.org/terms/). Version log : v002 - 2021/08/12. Annual update. 18 datasets, 38335 measurements in 8041 unique entries pertaining to 7248 distinct samples from 881 taxons. 7 parameters archived: d13C (n = 7690), d15N (n = 7491), d34S (n = 3266), %C (n = 5753), %N (n = 5614), %S (n = 3342), C/N ratio (n = 5719). Temporal coverage: 1989-2018. Spatial coverage: -76.7148° to 66.98283° latitude, -177.18503° to 162.2009° longitude. Max depth: 5338 m. v001 - 2020/10/22. Initial release of the database. 15 datasets, 18677 measurements in 4938 unique entries pertaining to 4378 distinct samples from 493 taxons. 7 parameters archived: d13C (n = 4587), d15N (n = 4388), d34S (n = 951), %C (n = 2740), %N (n = 2741), %S (n = 752), C/N ratio (n = 2518). Temporal coverage: 1985-2018. Spatial coverage: -62.1924° to 66.98283° latitude, -177.18503° to 152.105227° longitude. Max depth: 5029 m.