Large yields of high-viability human islets are necessary to service the expanding programmes of islet transplantation worldwide; similarly, there is an increasing demand from diabetes researchers for a reliable and cost-effective supply of human islets. The two main isolation methods are semi-automated and manual. Both methods rely on prompt and careful removal and transfer of the donor pancreas to allow isolation to commence, preferably within eight hours. Each method involves exocrine digestion with high-activity collagenase (Liberase). The semi-automated method is standardised, generally provides higher islet yields and is used for clinical transplant purposes, although it is not suitable for all donor pancreata. The manual method is less expensive and more adaptable and enables islets to be isolated for research from most donor pancreata.