The seeds of Foeniculum vulgare Gaertn. (Apiaceae) are used as spice as well as important medicinal purpose which is also famous in Bengal as Pan-mouhri as it is also used with beetle leaf. The seed production is depended on the successful pollination where insects played a major role as pollinators. Present investigation deals with the flower-visitors (insects) interaction, pollen production, pollen dispersal and pollination of Foeniculum vulgare Gaertn. The yellowish flowers appear during December - March. Flowers generally open in the morning (05:30-07:00 hrs.) and anther dehiscence takes place after flower opening. Each bisexual flower contains 5 anthers which produce a total 9850 pollen grains in average. After flower opening different insect flower visitors like members of Diptera (Flies, Syrphid flies), Hymenoptera (Apis dorsata, Apis cerena indica, Xylocopa sp., Amegilla sp., Vespa spp., Wasps, Ants etc.), Lepidoptera (Butterflies) and Coleoptera were found to visit the flowers for collecting their forage. During their visit they carry a considerable amount of pollen grains and transfer to other flowers for successful pollination for seed production. Among the visitors Apis spp. and Vespa spp. pay continuous visit for enhancing the pollination rate. The fruit production is considerably low when the insects were excluded which suggested the significant role of various insects for successful pollination.