Here we present lipid biomarker, geochemical and grain-size data of surface sediments from the western tropical South Atlantic collected during R/V METEOR cruise M125. We aimed to validate two commonly used lipid-based paleothermometers, the unsaturation index of alkenones (UK'37) and the TetraEther Index of tetraethers consisting of 86 carbon atoms (TEX86), along a transect on the Brazilian continental margin. The dataset contains alkenone, n-alkane, and Glycerol Dialkyl Glycerol Tetraether (GDGT) peak areas, elemental composition, bulk-geochemical parameters, grain size distribution, and derived results of the end-member analysis. Alkenones and n-alkanes were analyzed using an Agilent 7890 series II gas chromatograph equipped with an on-column injector and flame ionization detector (FID). GDGTs were analyzed with an Agilent 1260 Infinity II HPLC system linked to an Agilent MSD XT mass spectrometer following the methodology described by Hopmans et al. (2016; doi:10.1016/j.orggeochem.2015.12.006). The elemental compositions were determined by non-destructive energy-dispersive X-ray fluorescence spectrometry (ED-XRF) using a SPECTRO XEPOS P analyzer. Total carbon (TC), total organic carbon (TOC), and total nitrogen (TN) were analyzed using a Vario Micro Cube elemental analyzer. Analyses for grain-size classes ranging from 0.04 to 2,000 μm were conducted with a Beckman Coulter LS13 laser diffraction particle-size analyzer. End-member (EM) modeling of the unprocessed grain-size data was performed using the Matlab® -based software tool AnalySize 1.2.2. (Paterson & Heslop, 2015; doi:10.1002/2015GC006070).