The Cretaceous-Paleogene (K-Pg) mass extinction profoundly altered global marine ecosystems, yet deep-water environmental and biotic responses in distal settings remain poorly constrained. We present a continuous hydrocarbon biomarker record from deep-water sediments of the Pabdeh Section (Zagros Basin, Neo-Tethys Ocean) spanning about 10 million years across the K-Pg boundary. Our biogeochemical analyses reveal a significant environmental shift marked by a sharp increase in the pristane/phytane ratio from similar to 1.0 to greater than 3.0 following the extinction event, indicative of substantial redox changes potentially linked to impact-induced acidification, anoxia, and disrupted sulfur cycling. Two distinct episodes of water column stratification (elevated gammacerane index) further destabilised redox conditions during the Paleocene, and were, to some extent, associated with Deccan Traps volcanism. While marine primary productivity increased modestly in the earliest Paleocene, low sterane/hopane ratios (mean 0.3) demonstrate persistent bacterial dominance with limited, fluctuating algal biomass. A rise in C-30 steranes suggests that pelagophyte algae gained an ecological advantage under post-extinction oligotrophy. Wildfire-derived polycyclic aromatic hydrocarbons increased gradually, reflecting the prolonged disruption of terrestrial ecosystems. Our data reveal a complex and prolonged recovery phase in this deep-water setting, providing new insights into the long-term environmental and biotic changes following the mass extinction and highlighting the value of distal marine records. It emphasises the critical role of such distal palaeoenvironmental archives in understanding the nature of oceanographic responses to mass extinction.