Recently, a novel and promising biomarker proxy for reconstruction of Arctic sea ice conditions was developed and is based on the determination of a highly branched isoprenoid with 25 carbons (IP25). So far, IP25 records have been restricted to the last 150 kyr BP. Here, we present a biomarker record from Ocean Drilling Program (ODP) Site 912, going back to the Pliocene-Pleistocene boundary and indicating that sea ice of variable extent occurred in the Fram Strait/southern Yermak Plateau area at least since about 2.2 Ma. Furthermore, our data support the idea that a combination of IP25 and open water, phytoplankton biomarker data (“PIP25 index“) may give more reliable and quantitative estimates of past sea ice cover (at least for the study area). This study reveals that the novel IP25/PIP25 biomarker approach has potential for semi-quantitative paleo-sea ice studies covering the entire Quaternary and motivate to carry out further detailed high resolution research on ODP/IODP material using this proxy.