Highly differentiated processes relating to insulin-generating cells of the endocrine pancreas are covered by the term of nesidioblastosis. The disease is primarily characterised by persistent hypoglycaemia, and it affects newborns and young infants. Diffuse nesidioblastosis is predominant, as compared to focal processes. So called ductulo-insular complexes are characteristic immunohistochemical manifestations. While dietary and medicamentous therapies (diazoxide) usually failed to be effective, surgical removal so far has worked better than any other approach (subtotal and total pancreatectomy). Adequate early diagnosis should be established and pancreatectomy performed even before irreversible cerebral damage is caused by glucose deficit. Operations for subtotal or total pancreatectomy were performed on five children with nesidioblastosis at the Department of Paediatric Surgery in Erfurt, over the last two years. Epilepsy continued to be manifest in one of the five. Success eventually depends on close cooperation between paediatrics and paediatric surgery.