26% of 62 patients with Crohn’s disease had elevated serum levels of alkaline phosphatase and 58% of 38 patients showed impaired excretion of BSP; all the patients with hyperphosphatasaemia also showed increased BSP retention. There was no correlation of these tests with other indices of liver function which tended to be normal and no correlation with activity of the disease, duration of symptoms, age of the patient or the serum levels of albumin and cholesterol. Biochemical abnormalities due to liver dysfunction are common and should not be attributed to malabsorption.