Coparenting conflict is predictive of parents’ and children’s adjustment to divorce. An accurate assessment of postdivorce acrimonious coparenting relationships is critical for research, clinical, forensic, and public policy purposes. The Acrimony Scale (AS) is a measure commonly used to assess coparenting conflict. We translated and cross-culturally adapted the AS to the Portuguese context, testing its reliability and validity. Using a web-based survey, data were collected from a community and convenience sample of 196 unrelated divorced parents, assessing sociodemographic characteristics, coparenting conflict, and divorce adjustment. The study consisted of two phases: (1) forward-backward translation and cultural adaptation and (2) psychometric properties analyses: construct and criterion-related validity and internal consistency reliability. The 25-item AS was successfully translated and cross-culturally adapted to the Portuguese language. Principal component analyses (PCA) suggested a three-factor structure solution of 22-items, explaining 57.5% of the variance. Confirmatory factor analysis (CFA) showed the goodness of fit of this tridimensional model. The results also demonstrated acceptable convergent and good discriminant validity and high internal reliability. Scores on the AS suggested good known-groups validity and high discriminative power with 86.7% classification accuracy. The area under the ROC curve was 0.91, establishing a very good predictive value of the scale. We suggest that the AS is a reliable multidimensional measure to assess coparenting conflict after divorce and may be useful, namely, in the psychological assessment of child custody and evaluation of the effectiveness of coparenting conflict-based interventions. We discussed future research and practical implications.