Tissues obtained from infected Oreochromis niloticus
were processed sectioned and stained with haemotoxylin and eosin. Good sections were selected, studied and photographed. The histopathology revealed a proliferation of eosinophiles at the secondary lamellar of the gills. The site of attachment on the fish skin showed the cyst to be double walled, the metacercariea is suspected to produce this cyct as a form of defensive mechanism to wall off and prevent dislodgement. Other tissues did not show observable lesions.