The present investigation is the first contribution on the temporal distribution pattern of radiolarian fauna from the Northwestern Bay of Bengal (BoB). The present core spans up to 25 cal kyr BP based on the AMS ¹⁴ C radiocarbon dates obtained from planktonic foraminifera. The study documented the paleomonsoonal events for the past 7 kyr based on the quantitative distribution pattern of radiolarians. We report 26 radiolarian species among which 11 species are reported for the first time from the Northwestern BoB. In the present study, suborder Spumellaria was dominant (99.3 %) over the suborder Nassellaria (0.6 %). The radiolarian occurrence is noticed up to 7272 cal yr BP in the study area. In the Northwestern BoB, a strong monsoonal and high river discharge period is recorded during 7272–4424 cal yr BP, whereas weaker monsoonal period and aridification with episodes of increased upwelling activity is noticed during 4424–2678 cal yr BP. Simultaneous occurrence of intense monsoonal precipitation and upwelling activity is noticed between 2678 and 1000 cal yr BP. Alternate episodes of enhanced and decreased monsoonal activity associated with decreased upwelling events are recorded between 1000 and 800 cal yr BP and 800-Present time intervals, respectively. Thus radiolarian distribution in the study area was strongly influenced by the riverine discharge due to monsoonal precipitation and oceanographic conditions. Through this study, we propose the possibility of using radiolarian fauna as a proxy for paleomonsoonal as well as paleoceanographic studies.