In this article the so-called patient recall duty is discussed. More specifically, it has been determined if and when a physician should inform his former patients about newly discovered side effects relating to previously executed treatments. Although such an obligation may be surprising there are, in my view, sufficient arguments to justify the duty to perform a patient recall in some cases. The potential objections to the imposition of this duty do not alter my opinion. However, it is by no means the intention to impose on the physician a general post information obligation. In my opinion, two fundamental criteria should be taken into account in order to assess when the physician is obliged to carry out a patient recall, namely: the severity of the potential harm, and the foreseeability of the potential harm. This can be derived from similar existing criteria in other areas in which a recall obligation exists and from the case law concerning patient recall.