Since late 2007, the ice-breaking research vessel FS Polarstern of the Alfred Wegener Institute has been used as a voluntary observing ship (VOS) to collect measurements of the partial pressure of CO2 (pCO2) in the Atlantic Ocean and both polar regions. Oceanic and atmospheric pCO2 data are continuously collected with a General Oceanics pCO2 instrument (model “8050”), which is permanently installed in the ship’s wet lab. Ancillary data like air pressure, sea surface temperature and salinity are collected by the ship’s own data acquisition system. Integrated, fully quality controlled datasets up to the end of 2013 have been submitted to SOCAT (Surface Ocean CO2 Atlas), in which Polarstern data constitute the sixth largest contribution. Our data moreover originate from polar regions which are generally infrequently sampled due to low accessibility and thus are of particularly high significance to the SOCAT data base [1]. We outline data distribution and quality, and present a first assessment of the rate of increase of the oceanic pCO2 in the regions that were regularly visited.