This study aimed to examine the effects of 75 cardiac patients’ and their spouses’ illness cognitions of acceptance and helplessness on their own and their partner’s psychological symptoms, as well as the impact of marital quality. Dyadic responses were examined with the Actor–Partner Interdependence Model, while PROCESS was used to examine possible conditional indirect effects. Patients’ and spouses’ cognitions were related to their partners’ symptoms through the partners’ cognitions. These relationships were not statistically significant at the higher levels of marital quality. Thus, there seems to be a flow of information between partners, while marital quality may impact self-regulation processes.