Histopathology is a helpful indicator for environmental pollution. Histopathological analysis of fish tissue can be used to detect disease-related early warning signals as well as long-term harm to cells, tissues, and organs. The use of pesticides disturbs the aquatic food cycle, which is particularly harmful to fish. Neonicotinoids are among the several pesticides that interact with the nicotinic acetylcholine receptors (nAChR) in pests central nervous systems. Neonicotinoids gained popularity due to their high-water solubility, which allows for thorough penetration of the plant by their soil application. The first generation of neonicotinoids, of which imidacloprid is a member, are extensively used worldwide. Because of its widespread usage in agriculture, insecticides are present in the environment and may be toxicologically hazardous to fish. Monitoring histopathological alterations can be useful for assessing the pathological consequences of water-borne pollution and the histopathological changes that organic trace contamination has on fish organs. In the present study, exposure of Clarias gariepinus to Imidacloprid in various sublethal concentrations resulted in structural alterations excessive increased in myofibrils spaces, degraded muscle fibres, separation of muscle bundles, necrosis, swelling between muscle fibres, gap formation in myofibrils, oedema leading to disintegration and congestion of dermal blood cells.