We identify four patterns of diffusion that are likely to explain how trends in death penalty usage spread among countries. The first is geographic proximity, which creates dependency relations between nations that in turn affect the spread of changes in death penalty regimes. The second is global diffusion, meaning processes that spread ideas globally. The third is cultural homogeneity, which can be expected to be conducive for diffusion; studies show that countries similar in terms of language and religion influence each other to a great extent. Finally, similar colonial heritage, which can establish cultural and institutional ties between countries. This study encompasses all independent countries of the world over the period 1800 to 2021. In addition to measures of diffusion, a number of control variables are introduced. Relationships are measured using statistical techniques complemented by qualitative analyses.