Introduction/background Type 1 diabetes is a chronic autoimmune condition characterized by destruction of insulin-producing β cells within the pancreatic islets. It is associated with considerable morbidity and mortality. Incidence levels are rising worldwide. Sources of data Pubmed search (Nov 2010) using keywords: Type 1 diabetes, prevention, trials, immunotherapy. Areas of agreement The causes of disease are multifactorial with genetic and environmental factors playing a part. There is a long pre-clinical period before the onset of overt symptoms, which may be amenable to therapeutic intervention to prevent disease. Areas of controversy The exact nature of causative environmental factors is unknown and much debated. Immunotherapeutic intervention may therefore represent the best option for disease prevention. Growing points Enhancement of ‘regulatory’ immune mechanisms currently shows the most promise as an approach to disease prevention. Areas timely for developing research Clinical trials of early immunotherapeutic intervention may be the answer to disease prevention.