Bogue fish (B. boops, Linnaeus 1758) were captured using a seine net in the Lagoon of Lapseki, located in the Dardanelles, Turkey. We examined a total of 200 fish and assessed the hematological, biochemical, immunological parameters and histopathology of the buccal cavity of them (40 of them not parasitized, 40 of them parasitized). No significant difference was found between parasitized and not parasitized fish groups in terms of the average biometric indices, body weight and length values. Blood leucocytes counts, haemoglobin and hematocrit values, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, glucose, triglyceride, total protein, globulin, aspartate aminotransferase, NBT and lysozyme activity significantly reduced and bilirubin, alkaline phosphatase, creatine kinase, lactate dehydrogenase and myeloperoxidase activity significantly increased in C. oestroides parasitized fish compared to not parasitized ones. Infestation by this parasite resulted in histopathological manifestations such as hemorrhage, edema, necrosis, deformation in striated muscle cells, hypertrophy in chondrocytes and epithelial cells, mononuclear cell infiltration. According to the results obtained in the present study, it can be suggested that blood and histopathological variations influenced by parasites in the bogue fish can cause the fish to be more susceptible to pollutants, predators and diseases."