This dataset contains calcareous nannofossil flux data at DSDP Site 525 during the past 15 million years. Samples were prepared using the drop technique (Bordiga et al., 2015; doi:10.1016/j.revmic.2015.05.002) and nannofossil abundance was determined under the polarized-light microscope. Fluxes were calculated from the absolute abundances and the site-specific mass accumulation rates (data from Suchéras-Marx and Henderiks (2014; doi:10.1016/j.gloplacha.2014.10.015)) with reproducibility of ±15%.