The deep-sea planktonic microfossil record (foraminifera, coccolithophores, diatoms, radiolaria and dinoflagellates) provides a unique resource for palaeobiology. Despite some geographical gaps due to poor regional preservation, and intermittant time intervals lost to erosion, most time periods for each Cenozoic planktonic biogeographical province are preserved. Vast numbers of specimens and numerous deep-sea cores provide abundant material and the opportunity to tightly integrate macroevolutionary and palaeoenvironmental data. Current documentation of this record is mixed. Catalogues for foraminifera and coccolithophores offer nearly complete species-level clade histories, but taxonomy for siliceous microfossils is incomplete. Published occurrence data is primarily stratigraphic and covers only a fraction of the total preserved diversity. Age models for some sections are excellent (accuracy c. 100 kya) but for many other sections are still poor. Taxonomic errors, age model errors and reworking displace fossil occurrences in time, complicating palaeobiological analysis. With additional taxonomic work, careful collection of whole fauna/floral assemblage occurrence data, improved age models, and the development of better data filtering and analysis tools to deal with data outliers the deep-sea microfossil record can deliver its promise of providing the most complete, detailed record of macroevolutionary change available to science. SUPPLEMENTARY MATERIAL: Supplementary Appendix is available at http://www.geolsoc.org.uk/SUP18485