Psychiatric nurses' practice with parents who have mental illness, their children and families is an important issue internationally. This study provides a comparison of Irish and Australian psychiatric nurses' family-focused practices in adult mental health services. Three hundred and forty three nurses across Ireland and 155 from Australia completed the Family Focused Mental Health Practice Questionnaire. Cross-country comparisons revealed significant differences, in terms of family-focused skill, knowledge, confidence and practice. Australian psychiatric nurses engaged in higher family-focused practice compared to Irish nurses. The comparative differences between countries may be attributable to differences in training, workplace support and policy.