Clinical Impact Statement The results underscore the importance of personality traits to the understanding of postpartum psychopathological symptomatology, including posttraumatic stress disorder (PTSD), depression and mother-infant bonding difficulties. Further, the possible inverse association of postpartum PTSD childbirth-related and general symptoms with bonding difficulties should be further explored to better understand the possible debilitative as well as protective aspects of postpartum PTSD vis-a-vis mother-infant bonding. Such understanding would allow for better treatments offered to women suffering from postpartum psychopathology in general and childbirth-related PTSD symptoms in particular. Objective: As mother-infant bonding difficulties are potentially detrimental to child development, it is of importance to study its etiology and associated factors. Only a minority of studies have focused on the role of personality and postpartum depression and posttraumatic stress disorder (PTSD) in the etiology of bonding difficulties. The present article attempted to ascertain the association of vulnerability (Neuroticism) and resilience (Dispositional Optimism) with bonding, wherein postpartum depression and PTSD symptoms were possible mediators. Method: There were 504 mothers of infants, 0-13 months, who were sampled cross-sectionally using social media. Respondents completed an online survey consisting of the following questionnaires: demographic details, Neuroticism (subscale of the Big Five Inventory, BFI), Dispositional Optimism (Life Orientation Test-Revised), postpartum PTSD symptoms (City Birth Trauma Scale, BiTS), postpartum depression symptoms (Edinburgh Postpartum Depression Scale, EPDS), and mother-infant bonding difficulties (Postpartum Bonding Questionnaire, PBQ). Results: Path analysis revealed 5 significant indirect paths: Dispositional Optimism affected bonding through EPDS (beta = -0.04, p = .010) and through BiTS general symptoms (beta = -.02, p = .019), and BFI-Neuroticism affected bonding through EPDS (beta = 0.14, p = .001), BiTS birth-related symptoms (beta = -0.03, p = .013), and BiTS general symptoms (beta = 0.11, p = .001). Conclusions: Both Dispositional Optimism and Neuroticism correlated with bonding difficulties, mediated by postpartum depression and PTSD symptoms. When all variables were measured in a single model, postpartum PTSD birth-related symptoms predicted fewer bonding difficulties while general postpartum PTSD symptoms were associated with more bonding difficulties. Taken together, these results can promote better understanding of postpartum psychopathology and mother-infant bonding to allow for better treatments.