Despite considerable information and discussion about the risk of serious complications in patients with systemic mastocytosis undergoing general anaesthesia, little is known specifically about the risk to patients with isolated cutaneous mastocytosis. The experience of 29 general anaesthetics in 12 children with urticaria pigmentosa and three with solitary cutaneous mastocytoma was reviewed. No major complications were encountered and the four minor problems seen were self-limiting. The data from this study do not suggest that patients with urticaria pigmentosa or solitary cutaneous mastocytoma are at increased risk of life-threatening complications under general anaesthesia.