The chemical composition of fossil resins from Middle to Late Eocene lignite samples of the western margin of Bengal Basin, India, has been chemically analyzed to infer their botanical affinity. The terpenoid content of the resins has been characterized using gas chromatography–mass spectrometry (GC–MS). Sesquiterpenoid and triterpenoid components show close affinity with those in extant dammer (Dipterocarpaceae) resin (class II) and indicate the common occurrence of dipterocarps in the forest growing under warm tropical climate in the area at that time. Rich palynofloral assemblages dominated by Dipterocarpaceae pollen grains recovered from the lignite samples corroborate the chemical data.