This paper focuses on the cross-cultural adaptation of the Portuguese version of the Conflict Tactics Scales (CTS-1). Semantic equivalence was evaluated with regard to the referential meaning of words and the general connotative meaning of each item. Measurement equivalence between the Portuguese version and the original instrument was assessed by means of the version's psychometric properties, namely, intra-observer reliability, construct validity, internal consistency, and factor structure. For the different relationships, measurement agreement for physical aggression was moderate to substantial. Cronbach's a's were high for the physical and verbal aggression scales and low for the negotiation scale. As in the original instrument, factor analysis identified three dimensions, representing the negotiation, verbal aggression, and physical aggression scales, plus a severe physical aggression sub-scale. Although some problems still remain, the overall results suggest an adequate process of cross-cultural adaptation of the CTS-1, thus endorsing its use in the Brazilian setting.