Stomach contents analysis is a standard dietary assessment method that potentially enables quantifying diet components with high taxonomic resolution. We compiled diet compositions from stomach content analysis from 75 unique species or genera: 32 fish, 19 marine mammals, 14 elasmobranchs, 9 seabirds and one marine turtle. Data were gathered from 89 published sources that included samples collected between 1885 and 2016 throughout the central and Northeast Atlantic, and the Mediterranean Sea. When available, we reported the percentage number of individuals of a prey type as a proportion of the total number of prey items (%N), the proportion of a prey item by weight (%W), and the proportion of stomachs containing a particular prey item (i.e. percent frequency of occurrence, %F). For each data record, we also provided the sampling location, geographic coordinates, month and year of sample collection, method of sample collection, taxonomic ranks (phylum, class, order, family), number and size (or size range) of sampled organisms, as well as the reference and DOI of the original data source, for further details on the samples analysed and/or the analytical techniques used.