An investigation was made of the pathological, haematological and biochemical aspects of naturally-occurring bovine fascioliasis in the Sudan. 228 animals infected with Fasciola gigantica and 25 non-infected controls were used in the study. The infected cattle revealed emaciation, typical liver pathology, and, occasionally, lesions in the lung and the pancreas. Analysis of their sera also showed reduced albumin values, increased globulin concentrations and decrease albumin/globulin ratio, in addition to increased arginase activity. The serum iron concentration, on the other hand, was decreased, while the total iron binding capacity increased and the resultant iron saturation values reduced. Haematological findings in the infected animals included reduced erythrocyte counts, decreased haematocrit values, increased mean corpuscular volumes, eosinophilia and decreased neutrophil, lymphocyte and monocyte counts. Other parameters were similar in infected and control cattle.