This dataset includes chemical and isotopic measurements on shells of the planktic foraminifera Neogloboquadrina pachyderma sinistral, collected by plankton tows (MultiNet) from eight stations across the Fram Strait (sites ARK XV/2 77-84). The sampled depth intervals are 0-50 m, 50-100 m, and 100-200 m. Individual shells were analyzed in situ for their magnesium/calcium (Mg/Ca) ratios by Laser Ablation Inductively Coupled Mass Spectrometry (LA-ICP-MS), and for their stable oxygen isotope composition (d18O) by secondary ion mass spectrometry (SIMS). In addition, pooled shells were analyzed for d18O by acid-digestion isotope ratio mass spectrometry (IRMS). The purpose of this project was to determine the Mg/Ca:temperature sensitivity of the lamellar calcite (also called ontogenetic calcite) of N. pachyderma shells. Reference temperatures for the depth intervals sampled by MultiNet are available from parallel measurements using a conductivity temperature depth probe (CTD). A second objective of this project was to gain new insights into the d18O-temperature relationship of N. pachyderma by using two different analytical techniques (SIMS and IRMS).