1. To further investigate the possible role of glucagon in appetite control, weaned rabbits were auto-immunized using a glucagon-bovine serum albumin conjugate (G-BSA). 2. At weekly intervals, the animals were weighed and blood samples collected and subsequently analysed for insulin, glucose and glucagon concentrations. Weekly food consumption was also recorded. 3. At the termination of the experimental period, each animal was subjected to a glucose tolerance test. Following this procedure, the animals were killed and the livers excised and frozen for subsequent glycogen determination. 4. No differences between the controls and auto-immunized group were found at any time for weekly weight gain, food intake, blood glucose or insulin concentrations. 5. Glucagon concentrations in the control group remain stable over the 7 week period; however, after the third week of the experiment, no glucagon could be detected in the blood of any of the auto-immunized animals. 6. The auto-immunized animals had significantly different glucose tolerance profiles and also had significantly more liver glycogen than the control group.