Ranitidine is a histamine-2 blocker commonly prescribed in PICUs for the prophylaxis of gastrointestinal bleeding and stress ulcers. However, it can be associated to central nervous system side effects, such as delirium, in adults. We present the first case of a child presenting delirium possibly caused by anticholinergic toxidrome secondary to the use of ranitidine, resolving after drug discontinuation. With this case report, we reinforce that a wide variety of clinical conditions can trigger delirium and that the best therapeutic approach is to minimize risk factors.