Between January 1987 and September 1989 three children presented to the childrens' casualty department with spontaneous hyphaema. Physical examination and haematological investigations were sufficient to determine their cause in two cases (sickle cell disease and acute lymphoblastic leukaemia). In the third child an ophthalmological examination under general anaesthesia revealed a granulomatous lesion of the iris consistent with the diagnosis of juvenile xanthogranuloma.