A report on the authors' experience with 391 paediatric patients treated from 1st January 1984 to 31st December 1988 by oral or i.v. administration of ranitidine is presented. The patients were divided into two groups, one taking ranitidine for specific gastro-intestinal disorders and the other suffering from a variety of non-gastro-intestinal diseases and receiving ranitidine for prophylactic purposes. Analysis of the patient sample clearly showed the need for a safe, effective H2-antagonist such as ranitidine in paediatrics both in the treatment and in the prevention of peptic ulcer disease