--- - |2+ Abstract Objective This study aimed to examine the relationship between dysfunctional motherhood‐related beliefs and postpartum anxiety and depression symptoms, and whether experiential avoidance may be a potential mechanism in explaining these relationships. Method A sample of 262 postpartum women participated in a cross‐sectional online survey. Results The model presented a good fit (CFI = 0.96, RMSEA = 0.077) suggesting that more dysfunctional motherhood‐related beliefs related with maternal responsibility and with others’ judgments were associated with higher postpartum anxiety and depressive symptoms. Indirect effects through experiential avoidance were also found. Conclusions Dysfunctional motherhood‐related beliefs are cognitive vulnerabilities for postpartum psychological disorders and should be assessed to identify women that may be prone to early interventions. Moreover, dysfunctional beliefs seem to affect psychopathological symptoms by activating experiential avoidance strategies (e.g., rumination), which may accentuate the frequency of women's negative thoughts and emotions. Early interventions should target the promotion of acceptance of private negative experiences (psychological flexibility). - Journal of Clinical Psychology, EarlyView.