Homogenates from the terminal ileum of a patient with Crohn's disease with granulomas were prepared as snap-frozen or fresh and were injected into the ascending colonic walls of New Zealand white rabbits. Control animals were injected with 1 per cent bovine serum albumin alone. The rabbit bowel was examined after 1 year, and lesions were noted in each of the rabbits injected with Crohn's disease homogenate, irrespective of the type of tissue preparation. The observed lesions were diffuse and occurred both at the injection site and in the terminal ileum. These changes were not noted in the control group. This work confirms earlier results in the same animal model and suggests that either fresh or snap-frozen homogenates will produce the intestinal lesion but that bovine albumin alone will not.