Abstract
In medical scientific research much use is made of human bodily material (residual tissue) which remains after treatment or diagnosis. Using this, relevant research questions can be answered. The way in which patients can consent to the secondary use of residual tissue is now formalised in a code of conduct, which allows such use unless the patient has objected to this use ('opting-out' procedure). A law is being formulated which will probably require the explicit permission of the patient for secondary use of residual tissue. It is expected that this requirement will lead to a lesser and more selective availability of residual tissue for research. Requesting explicit permission also means additional health care work. Patients demonstrate a preference for the 'opting-out' procedure, on condition that they are well informed about the use of the residual tissue. It is concluded that the interests of the patient are best served by the 'opting-out' procedure, provided that patients are well informed.