This study reports contagion and interdependence of quarterly debt to gross domestic product (GDP) among the member states of the Eurozone over the period 2000 Q4 to 2012 Q1. We test for contagion and interdependence in two steps. First, we define an indicator variable of increasing debt to GDP for each country during the period following the United States financial crisis, by using unit root tests incorporating structural changes and breaking trend regressions. Second, the indicator variable is included in the latent-factor panel data model to separate contagion and interdependence of debt to GDP among Eurozone member states. Results show significant and country-dependent contagion and interdependence effects of debt to GDP in the Eurozone.