An elisa with a diagnostic sensitivity of 98 per cent and specificity of 96 per cent was evaluated as a means of assessing the intensity of Fasciola hepatica infection in cattle. A total of 294 blood samples were collected from infected cattle at a local abattoir, and the level of infection in each animal was assessed on the basis of the extent of liver pathology and the presence of flukes; 120 blood samples were also collected from uninfected cattle kept on a farm known to be free of F hepatica. The results indicated that there was a significant correlation (P<0.001) between the elisa values and the intensity of infection. Values between 15 and 28 per cent of a positive control sample indicated a low intensity of infection, values between 28 and 50 per cent indicated a medium intensity of infection and values above 50 per cent indicated a high intensity of infection.