Islet transplantation can deliver stable glycemic control, relief from recurrent severe hypoglycemia, and insulin independence. Accessing the portal vein via the percutaneous hepatic approach carries the risk of bleeding, and the infusion of islets a risk of portal vein thrombosis. In the long term, common minor problems with immunosuppression are mouth ulcers, diarrhea, and acne. Longer-term risks include malignancy and serious infection, both rare to date in clinical islet transplantation. Sensitization to donor antigens may also occur. The long-term diabetes complications may stabilize, but of this aspect little is known to date. In the short term, there may be some elevation of serum cholesterol and blood pressure, in some patients there has been a decline in renal function, and in a few, acute retinal bleeds. For most, improvement in glucose control with resolution of glycemic lability and hypoglycemia has been a net benefit.