This study was carried outto investigate some of the internal parasitic diseases of digenetic origin that affect Clarias gariepinus. 160 fish were collected randomly and seasonally from different sources in Ismailia governorate. Examined fish showed no pathognomonic clinical signs especially in low parasite load. P.M. lesions were mostly paleness or congestion and enlargement of the liver with pin head spots. Total infestation rate was 75%. The isolated flukes were Orientocredium sp., Astiorema reniferum, Eumesenia sp. as well as encysted metacercariae. The infestation rate increased with the increase of the body weight and length. Infestation in females were higher than males especially during spring and winter seasons. PCR used for identification of trematodes by using (ITS2) giving positive band at 539bp. The histopathological changes recorded were mostly degeneration, necrosis, sloughing of cells and infiltration.