Olfaction is the major sense of smell in teleost involved in many physiological response and habitat acclimatization including food searching, migration for spawning, predator avoidance, reproduction behavior, as well as identification of fish of the same species. Our study illustrates the ultrastructure of the olfactory rosette of the Anguilla vulgaris, Ctenopharyngodon idella by using Scanning Electron Microscope. Herein, the peripheral olfactory organs are represented by two olfactory rosettes lying in two nasal chambers, one on each side of fish snout. Each nasal chambers opens to the exterior by two nostrils a narrow inlet and wider outlet, segregated by a somewhat elevated, nasal bridge. The two nostrils are somewhat as far as length of rosette's length to permit entering and leave water flow bearing odorant molecules to the nasal cavities. In Anguilla vulgaris, each chamber's olfactory rosette is oval, and the number of olfactory lamellae in the olfactory rosette grows as the body length increases. There were 45 to 48 lamellae in the olfactory rosette. The sensory epithelium covers the lateral surface of the olfactory lamella, while the non-sensory region is mostly restricted to the lamellae's margins. Ciliated, microvillous olfactory receptor cells, crypt, and rodlet cells were found in the sensory epithelium. Supporting cells such as basal and microvillous cells are also present. Rodlet cells and stratified epithelium made up the non-sensory epithelial cells.