In recent years, measures have been taken to ban the use of international legal principles in state courts. While these international laws vary in terms of the specific restrictions they place on state legal practices, many of these laws have been aimed implicitly or explicitly at banning Sharia law practices. While dozens of states have attempted to pass anti-Sharia policies, thus far, only eight have been successful. In this article, we apply a policy diffusion framework to help explain the agenda placement and adoption of these measures. We find that both internal state determinants and external regional diffusion factors influence the interstate agenda placement and adoption of anti-Sharia practices. However, the regional effect is negative, meaning that these policies follow an atypical diffusion pattern. This study adds to the growing body of literature that examines the diffusion of controversial morality policies.