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.