Sanguinicola species become very important dangerous blood parasites, infested culture wild fishes and caused damge for or yours of infested fish species specially CLarias gariepinus. The examination of gills, heart, kidney, liver and spleen revealed that present live blood fluke in some organs e.g. heart. The parasitological examination for Clarias gariepinus revealed that the prevelance of Sanguinicola species infestation was (63.33%). The clinical signs of examined infested fish showed that fish swim slowly and listlessly, anaemic and gills of infested fish were pale in colour. The histopathological changes in gills of infested Clarias gariepinus with Sanguinicola sp < /em>. showed unilateral sloughing of secondary lamellae and congested branchial blood vessels with presence of edema and intense leukocytic aggregation in gill arch. In heart present intermuscular edema, leukocytic infiltration among degenerated muscle fibers and intense hyaline degeneration or myolsis among muscle fiber. In liver showed edematous vascular wall, lymphocytic infiltration and degeneration in hepatic cells. In hepatopancreas present degranulation, hemorrhages and melanomacrophage aggregations with diffuse necrosis of hepatic parenchyma. In spleen showed depleted haemopiotic and lymphoid elements. In posterior kidney revealed focal hemorrhagic areas, hyaline degeneration in tubular nephrosis and contracted glomerular tufts. Effect Sanguinicola sp < /em>. infection on Clarias gariepinus was evaluated blood haemogram including total RBCs count, total leucocytic count, packed cell volume (PCV) and hemoglobin concentration. Also serum analysis of biochemical parameters including total protein and liver and kidney functions. The total RBCs count, hemoglobin concentration and PCV value were significantly decreased but total leucocytic count were very highly significantly increased due to increase  in antibodies levels. The total proteins were very highly significantly decreased. Serum AST and S.ALT showed high significant and significant increase respectively and serum creatinine were highly increased significantly. The treatment trial was held by using (Praziquantel - Bayer) Droncit in 10 mg/L for 1 hour for 4 days. Blood analysis of fish free from blood fluke       (Sanguinicola sp < /em>.) revealed increase highly significantly in total RBCs count, hemoglobin concentration and packed cell volume. Total protein and total WBCs count were very highly decreased in compared with infested fish.