Human tissue remaining after diagnostic procedures is important for use in scientific research. This 'secondary use' of tissue is regulated by the Dutch Medical Treatment Contracts Act and the Code of Conduct for Proper Secondary Use of Human Tissue of the Dutch Federation of Biomedical Scientific Societies. Patients have the right to opt-out of further use of their residual tissue, but the procedures for objection and the provision of information involved are not regulated by statute. Dutch patients have a positive attitude to further use of human tissue for other purposes. They prefer, however, a procedure in which they are informed verbally by their health professional about research with residual tissue. The information can be brief and is best provided early in the treatment. Administrative and technical modifications of the current registration systems are necessary to support the opting-out procedure in practice. By taking the preferences of patients into account, trust in medical practice can be maintained.