The pica phenomenon, where non-edible substances are repeatedly consumed, has been linked with developmental and behavioural disorders, particularly autism. The clinical presentation of foreign body ingestion in patients with autism is discussed, and recommendations for caregivers are provided based on the available literature. An 18-year-old man with severe autism and behavioural difficulties presented with a vague history of decreased appetite and melaena of eight months duration. Foreign body ingestion commonly occurs in individuals with autism spectrum disorders and should be suspected in patients who present with vague gastrointestinal symptoms. The adverse medical and surgical consequences of foreign body ingestion emphasize the need for early recognition. Surgical intervention for foreign body ingestion can prevent complications. Magnetic substances can cause considerable gastrointestinal morbidity and require urgent endoscopic or surgical removal. Primary prevention is also vital. (Contains 2 figures.)