Research question The secondary use of clinical data for research and learning activities has the potential to significantly improve medical knowledge and clinical care. To realize this potential, an ethical and legal basis for data use is needed, preferably in the form of patient consent. This raises the question: Do patients have a moral duty to provide their clinical data for research and learning activities? Methods On the basis of an ethical approach that we call “caring liberalism,” we evaluate plausibility (...) and moral weight of the following arguments in favor of a duty on patients to provide their clinical data for research and learning activities: the general duty to help; solidarity; the duty to act in the public interest; the free-rider argument; transgenerational justice; the principle of giving back; the do-not-harm principle; freedom of research and the value of science. Results The general duty to help and the duty to act in the public interest are strong reasons for a moral duty of patients to provide their clinical data for research and learning activities. Transgenerational justice and the principle of giving back are ethically weak reasons for such a duty but might be motivational factors. The other reasons are not appropriate to justify a duty. The results are relevant in several respects: for patients who are asked to consent to the secondary use of their clinical data; for the ethical discussion of the question whether and to what extent deviations from the classical specific consent are ethically justifiable under certain conditions; for the legal discussion of the conditions for a proportionate secondary use of clinical data for research and learning activities. (shrink)