The growing gap between the number of organs available for transplantation and patients on waiting lists demands additional donor sources. Nonheart-beating (NHB)-donor programs are known to increase the number of kidneys available. The group of potential NHB donors is very diverse and therefore 4 categories have been identified. At the University Hospital Maastricht, a NHB-donor program was implemented in 1980 to harvest kidneys after an in situ perfusion technique. In order to evaluate the function of kidney grafts from NHB donors, a retrospective multicenter study on the NHB-donor kidneys transplanted until 1992 was performed, using a control group of kidneys from heart-beating (HB) donors. The short-term results showed more delayed function (DF) in the NHB-donor group accompanied by higher serum creatinine levels at one-month posttransplant. The long-term outcome, however, was equal in both groups showing similar graft and patient survival rates up to 5 years. Apart from the type of donor, HB or NHB, only the number of HLA-DR mismatches could be identified as a potential risk factor for delayed graft function. NHB donors contribute considerably to reducing the gap between offer and demand in kidney transplantation and transplant centers should include NHB donors in their procurement programs. Meanwhile, efforts should be made to improve the short-term posttransplant graft function. Together with reducing DF, searching for valuable tools in viability assessment should also be an objective. Past viability tests never found broad clinical use but might be important in the optimal and safe usage of the potential NHB donor pool.