In recent years, scholars have increasingly turned to quantitative research methods to understand the impact of transitional justice (TJ) on societies emerging from periods of violence and repression. This research often seeks to influence policy diffusion by making bold claims based upon large datasets of TJ events that span space and time. However, the policy advice from the first wave of quantitative research is inconsistent if not contradictory. In this article, we outline a range of methodological issues that help to explain the different conclusions reached by these studies, including sampling strategies, model construction, and the measurement of key variables. Furthermore, these studies have often failed to provide compelling theoretical or empirical bases for a causal relationship between TJ mechanisms and dependent variables such as democracy and human rights. We suggest several ways in which quantitative scholars could produce findings with broader credibility. Although we support the use of quantitative methods to understand the impact of TJ mechanisms, greater methodological care is needed in supporting policy recommendations