When does leadership decapitation against terrorist groups cause their demise? This article reviews the existing body of literature concerning terrorist leadership targeting and identifies limitations in the prevailing approaches. As past attempts to gauge the efficacy of decapitation strategies are disputed, this article calls for a new methodology for conducting decapitation research. Deriving from two themes in the security literature—works on leadership targeting in conventional warfare and counterterrorism, as well as studies of “informal” terrorist actors—this article proposes that analysts and policymakers adopt a holistic framework for organizing knowledge around leadership decapitation. The author conceptualizes a model of leadership decapitation by dividing it into strategic, operational, and tactical levels of targeting with respect to both formal and informal terrorist actors. Empirical examples are drawn from U.S. and allied decapitation attempts against members of al-Qaeda and other actors in the broader movement for global jihad. Although the framework does not attest to the effectiveness of leadership targeting, it is a theoretical starting point implying new avenues for evaluating terrorism data. Consequently, this article elucidates research and policy implications for leadership decapitation in counterterrorism.