•Model based calculations of black carbon–air partition coefficients for PCBs.•Soil and air levels of PCBs reported first time for ecologically important sites of Indus River Basin, Pakistan.•Black carbon showed influential role in soil–air partitioning of PCBs in Indus River Basin, Pakistan. Levels of polychlorinated biphenyls (PCBs) were assessed in surface soils and passive air samples from the Indus River Basin, and the influential role of black carbon (BC) in the soil–air partitioning process was examined. ∑26–PCBs ranged between 0.002–3.03pgm−3 and 0.26–1.89ngg−1 for passive air and soil samples, respectively. Lower chlorinated (tri- and tetra-) PCBs were abundant in both air (83.9%) and soil (92.1%) samples. Soil–air partitioning of PCBs was investigated through octanol–air partition coefficients (KOA) and black carbon–air partition coefficients (KBC–A). The results of the paired-t test revealed that both models showed statistically significant agreement between measured and predicted model values for the PCB congeners. Ratios of fBCKBC–AδOCT/fOMKOA>5 explicitly suggested the influential role of black carbon in the retention and soil–air partitioning of PCBs. Lower chlorinated PCBs were strongly adsorbed and retained by black carbon during soil–air partitioning because of their dominance at the sampling sites and planarity effect.