Health-care research relies largely on human materials stored in highly specialised biorepositories. Medical translational research on tissues can be performed using a variety of resources in distinct situations. The best known is the secondary use of pathology archives where paraffin-embedded tissues are stored for diagnostic reasons. Another is collecting and storing frozen material obtained from leftover surgical diagnosis. Such residual tissues can either be used directly in research projects or used in the context of a clinical trial with new interventional medicinal products. The latter can make the regulations governing the use of these materials for medical research much more complicated. The use of residual materials is very distinct from biobanking projects for which tissue is specifically collected. This article describes the consequences of using residual human material from different sources in distinct situations and why signed informed consent is not always the preferred choice of individual countries regarding the use of residual material. In addition, signed informed consent is overdone when using residual tissues in medical research. We maintain that the opt-out system is a balanced choice if certain requirements are met, relating to sufficient transparency about using residual tissue for research, the purpose of such research and to the confidentiality of the data used in that research. Finally, the international exchange of samples can be based on the laws and regulations of the countries of origin. Respecting these form the basis of what can and cannot be done in the country where the research on the samples is being performed.