1. Viable and functional islets can be recovered from human pancreata stored for prolonged periods (up to 18 hours) with either the UW solution or EC. 2. Function of islets from pancreas stored in UW solution appeared superior. However, the difference in these preliminary studies does not appear nearly so dramatic as in transplantation of vascularized pancreas. 3. Function of islets from human pancreas stored for longer than 18 hours after UW in situ flush was uniformly poor. 4. Considerable room for improvement in the storage of human pancreas before isolation exists. Progress in this area will be important for the development of any large-scale program of clinical islet transplantation.