Unwanted pursuit behavior (UPB) refers to a wide range of repeated, unwanted, and privacy-violating intrusions that are inflicted to pursue an intimate or romantic relationship. These behaviors most often occur when partners end their romantic entanglements. Despite the fact that UPB is grounded in relationships, psychological explanations for postbreakup UPB perpetration have been restricted to actor effects assessed in samples of separated individuals. For that reason, the present study aimed to identify feasible partner effects that additionally explain UPB perpetration using a Flemish sample of 46 heterosexual divorced couples, beginning with the notion of interdependence. Using actor–partner interdependence models, we explored actor, partner, and gender main and interaction effects of anxious attachment, satisfaction, alternatives, investments, and conflict in the previous marriage on the perpetration of postdivorce UPBs. The significant Partner× Gender interactions of anxious attachment and satisfaction, Actor× Partner interactions of anxious attachment and quality of alternatives, and the marginally significant partner effect of relational conflict underline the important role of the dyad in studying UPB perpetration. These findings shed new light on the nature of UPB perpetration that go beyond the individual and support the use of a systemic approach in clinical practices.(PsycInfo Database Record (c) 2020 APA, all rights reserved)