Countering financing of terrorism (CFT) has been a core component of counter terrorism strategies since the 9/11 attacks on the US in 2001. Key CFT measures are criminalisation of terrorism financing; sanctions and assets freezing/seizure; and use of financial intelligence. CFT assessments focus on implementation of these measures, rather than on impact in terms of preventing terrorist activity. This rapid review therefore looks at the effectiveness of different CFT measures. It draws on a mixture of academic and grey literature, including policy papers and reports from agencies involved in CFT implementation. While there is available literature on terrorism financing (how groups raise funds), and on the various approaches to CFT as well as implementation assessment, the review found very little on the impact of CFT in preventing terrorism. Reflecting this, it was also difficult to identify specific examples of CFT impact and effectiveness. The limited literature on the latter suggests that, while CFT measures can hamper terrorists/terrorist groups, they cannot stop them entirely. Despite this, CFT remains a useful tool for governments in the fight against terrorism/their efforts to counter terrorism. However, the current CFT model needs to be reformed to address significant changes in both the terrorist threat and terrorism financing environment.