The organizing institution of a biobank can be of public or private law in nature and the form can be freely selected. Biomaterials must be legally valued as objects whereby inalienable personality rights are still valid even if ownership is transferred. The treating physician does not automatically acquire a comprehensive right of ownership or utilization for the materials taken during the treatment. The biobank acquires tangible property and user rights on the samples by a legal agreement between the donor and the biobank. Reutilization clauses in submission contracts should not be used due to the danger of a formularization development and surprise clauses. During the processing of biomaterials within the biobank substantially new characteristics can appear which have an effect on ownership and commercialization rights. The donor does not have a utilization right in the sense of a patent or copyright. If there are changes in the legal form and the use by third parties, the declaration of consent by the donor remains fully effective. There are special risks for the donor if the biobank transfers these biomaterials. This must be clarified before finalizing the agreement on sample transference and utilization in the sense of an informed decision.