The present study investigated: (a) the mediating effect of perceived intimate partner rejection in the relationship between remembered parental rejection and social anxiety, and (b) the moderating effect of gender in the relationship between remembered paternal and maternal rejection and social anxiety. The sample was consisted of 365 Greek university students (266 female; 99 male; 18–48 years) and data collection was made with self-report questionnaires measuring demographic characteristics, remembered paternal and maternal rejection, perceived intimate partner rejection, and social anxiety. The indirect (mediation) and conditional (moderating) effects were examined using the PROCESS program. Results showed that perceived intimate partner rejection mediated partly the relationship between both remembered paternal and maternal rejection and social anxiety. It was also found that remembered paternal and maternal rejection in childhood have a greater impact on the levels of social anxiety in adulthood for men than for women. Implications for future research and effective therapeutic interventions for socially anxious individuals are discussed.