A study was conducted on the impact of the biomass burning plumes transported from the Eastern Ghat regions on the chemical characteristics of the size-segregated aerosols over Kolkata, a tropical megacity situated at the eastern Indo-Gangetic Plain. A Micro Orifice Uniform Deposit Impactor (MOUDI) was used to collect the size-segregated aerosols with and without the influence of transported biomass burning plumes during premonsoon (March–May), 2016. Satellite observations revealed the presence of thick polluted aerosol layer during the fire episodes whereas clean marine aerosol layer was observed during the normal episodes over Kolkata. Transported plumes enhanced the fine mode aerosols whereas the coarse mode aerosols remained unaffected. PM1.0-0.1 and PM0.1 were greatly affected by the transported plumes with the increase by three folds during the fire episodes. K+, NH4+ and SO42– showed significant increases in the accumulation mode (PM1.0-0.1) under the influence of biomass burning plumes whereas NO3– showed an increase in coarse mode aerosols. Transported plumes did not change the mass-size distribution patterns of K+, NH4+ and SO42– (unimodal fine mode dominant) whereas NO3– showed a change from bimodal to unimodal coarse mode dominant distribution under the influence of transported plumes. It was observed that the biomass burning plumes interacted well with the accumulation and superfine mode (PM0.1) sea-salt particles leading to the depletion of chloride. The maximum chloride depletion (~80%) was observed in the size range of 0.56–0.32 µm. It was observed that non-sea-SO42– was the key constituent responsible for the chloride loss from sea-salt particles. The biomass burning plume was found to have the potential to change the mass-size distribution pattern of the total aerosols from the coarse mode to the fine mode dominant.