Isoprene, emitted mainly by tree species, is a highly reactive and second most abundant biogenic volatile organic carbon (VOC) in the atmosphere. It produces tropospheric ozone and other secondary organic pollutants. We hypothesize that the soil of tropical dry forests, one of India’s major forest types, may serve as a significant sink for isoprene. To address the issue, we enriched the under-canopy soils of isoprene-emitting tree species (Tectona sp., Butea sp., Madhuca sp.) with 10, 40, 70 and 100 ppm isoprene concentrations for a week. Isoprene oxidation (pg g−1 h−1 dws) varied significantly with the season showing maximum oxidation in the rainy season (120.59 to 956.22) followed by winter (106.58 to 842.5) and summer (102.17 to 805.56). However, the effect of tree species on isoprene oxidation was not significant. The qPCR-based bacterial population (16S rRNA gene copy number; copies 109 g−1dws) analysis showed higher value during rainy season (13.75–18.90) followed by winter (2.67–6.19) and summer (2.10–4.51). Isoprene oxidation showed strong dependence on bacterial population (r = 0.93; p < 0.05). Higher values of kinetic constant K during rainy season also supported higher oxidation of isoprene in this season. Overall, the findings suggest that tropical dry forest soil favors growth and activities of bacterial populations during warm and wet periods of the year which consume significant amounts of isoprene.