Childhood maltreatment is considered a crucial explanatory variable for intimate partner violence (IPV) in adulthood. However, a developmental multifactorial model for the etiology of IPV is not shared by researchers yet. This study has investigated the role of a wide range of childhood maltreatments and family and social dysfunctions in predicting IPV; furthermore, it tests a model where childhood maltreatment mediates the relationship between environmental dysfunctions and IPV. The sample included 78 women: IPV (38) and non-IPV (40). The Italian version of the Childhood Experience of Care and Abuse (CECA) Interview was used to assess the presence of adverse childhood experiences. The Revised Conflict Tactics Scale (CTS-2) and the IPV History Interview were used to assess IPV in the last year and lifetime, respectively. The results of a multivariate logistic regression model have indicated that only sexual (odds ratio [OR] = 4.24) and psychological (OR = 3.45) abuse significantly predicted IPV; with regard to association between IPV and environmental dysfunctions, only poor social support (OR = 8.91) significantly predicted IPV. The results of a mediation model have shown that childhood psychological and sexual abuse, in association with each other, partially mediate the relationship between poor social support and IPV. The findings from this study pinpoint poor social support as an important predictor of IPV so far neglected in the literature on the developmental antecedents of IPV. They also support the theoretical assumption according to which dysfunctional environmental variables and types of childhood maltreatment interacting with each other may influence development outcomes.