This paper empirically tests the influence of transitional justice mechanisms (TJMs) – particularly truth commissions and war crimes tribunals – on post-civil war societies. The transitional justice literature advocates the effectiveness of such mechanisms in bringing about the reconciliation necessary to facilitate democratization and respect for human rights. However, few cross-national empirical studies exist to evaluate these claims. This article compares current levels of human rights abuses and democratization in post-civil war countries that have used TJMs with post-civil war countries that have not. These results support the advocates of war crimes tribunals: countries that have used tribunals have higher levels of democratization and human rights than societies that did not. However, the results show that truth commissions have less influence on democratization and human rights