Objectives: To determine the self-reported prevalence of child and partner physical and emotional abuse in the north of Portugal and to investigate attitudes about these forms of family violence. Methods: Data were collected by questionnaire from a representative sample of parents in two-parent families with children under the age of 18 years. A total of 2,391 parents participated (1,057 males), aged 20-67 years. Four questionnaires were used, one behavioral and one attitudinal, for each of the forms of abuse: child and partner. Results: At least one act of emotional or physical abuse towards a child during the previous year was reported by 25.9% of participants (12.3% reported physically abusive and 22.4% emotionally abusive acts). Abuse of a partner was reported by 26.2% of participants; at least one act of physical abuse during the previous year was reported by 12% and of emotional abuse by 23.7%. The attitudinal data, however, showed general disapproval of the use of violence, both for disciplining children and within marital relationships. The degree of self-reported support for physical punishment was higher in participants who reported using abusive behavior. Females more commonly reported acts of child abuse, and males reported acts of partner abuse. Both forms of self-reported abuse showed an association with low educational and socio-economic status. Conclusions: This is the first study in Portugal to analyze family violence through self-report using a representative sample. The findings indicate that child and partner abuse constitute a significant problem in the region of northern Portugal. The discrepancy between the self-reported behavioral and attitudinal data may reflect conflicts in Portuguese society, which is undergoing substantial cultural changes.