Individuals with social anxiety disorder (SAD) experience heightened concern about rejection and negative evaluation by other people. However, limited research has assessed the extent to which individuals with SAD also experience elevated concerns about rejection within the context of their intimate relationships. In the present study, individuals with SAD (n = 21) and healthy controls (HCs; n = 25) who were in current intimate relationships completed daily diaries each evening for 14 days. Daily diaries assessed the extent to which participants experienced feelings of rejection and acceptance in their intimate relationships, as well as the extent to which they responded to feelings of rejection by using behaviours characterized by withdrawal (“withdrawal” processes) versus efforts to reaffiliate with their partners (“approach” processes). Results revealed that individuals with SAD reported greater levels of intimate partner rejection and marginally lower levels of intimate partner acceptance than HCs. Further, feelings of rejection were associated with an increased use of next-day withdrawal processes among SAD, but not HC participants. These findings provide insight into the nature of rejection concerns and responses to rejection among individuals with SAD.