Abstract
                                                                The morphological description and histological structure of the olfactory     organ     of    Parasilurus     triostegus     (Heckel)     have    been investigated. The olfactory organ situated on the dorsal surface of the head infront of the eye. It  is  represented   by  elongated  olfactory  sac,  in  which  the olfactory Lamellae arranged as Rosette- like pattern .The olfactory sac connected with the olfactory bulb by short olfactory nerve. The olfactory bulb which situated near the olfactory sac connected with the olfactory lobe through a long olfactory tract.