Germany's Social Democracy is in demise. The party's electoral fortunes are abysmal and its membership basis is dwindling. This paper contributes to an edited volume on the structural problems of European Social Democratic parties. It analyzes in great empirical detail the causal factors that have contributed to the demise of the former catch-all cewnter-left party. Empirically, it draws on political party publications, interviews with party leaders, analysis of relevant secondary literature and parliamentary debates. It also presents electoral results from national and regional elections. Conceptually, there are six core factors that have contributed to the decline of the SPD's fortune: the corrosion of the socioeconomic milieu, the lack of programmatic coherence and clarity regarding key political economy challenges of the 21st century, the demise of the links to the working class, unclear answers to the pressing questions regarding future welfare reform, an out-of-touch stance on immigration and integration and a less than articulate position regarding a center-left vision on European integration. The paper contributes to the growing literature that explores the root causes of flux and turmoil in contemporary European party politics.