Ghrelin, released from the stomach, acts at the hypothalamus and is associated with initiation of food intake. We hypothesised that patients with craniopharyngioma and hypothalamic obesity (CRHO) would have ghrelin abnormalities. Fifteen CRHO patients and 15 BMI-matched controls underwent oral glucose tolerance test with dynamic ghrelin measurement. From 0-30 minutes, ghrelin (pg/ml) decreased less (43.4 ? 38.8 vs. 70.8 ? 35.8, p < 0.05) and insulin (pmol/l) increased more (1 669.2 ? 861.7 vs. 1 049.1 ? 560.4, p = 0.04) in CRHO compared with controls, respectively. Insulin area-under-the-curve was a weak negative predictor of the 0?30 minutes ghrelin decrease (r(2) = 0.29, p = 0.02). Delayed ghrelin suppression may contribute to obesity in CRHO.