Islet cell transplantation is an attractive alternative therapy to conventional insulin treatment or whole vascularized pancreas transplantation for type 1 diabetic patients. It can restore endogenous insulin secretion, achieve insulin independence, and reduce risk of recurrent hypoglycaemia and of diabetic complications. Islet cell transplantation should also be indicated after total pancreatectomy. This procedure allows open abdominal surgery to be avoided; it can be performed under local anaesthesia and is therefore less invasive and cheaper than whole pancreas transplantation. This article reviews basic informations about the islet recipient approach, methods of islet isolation, purification and transplantation as well as about immunosuppressive treatment and clinical complications connected with the whole procedure.