This article presents findings from the 2015 UN Office on Drugs and Crime (UNODC) Study on firearms trafficking, which was based upon information collected from 48 governments. It outlines the methodology and sources used in the UNODC Study, and discusses their strengths and limitations. The UNODC Study is then located within three wider bodies of research on firearms trafficking. Three key findings from data reported by the states that took part in the Study are summarized. In those states firearms trafficking is mostly small scale and local – occurring across neighbouring borders or within regions. Trafficked firearms tend to be obtained by people engaged in other forms of criminal activity. In many states there is a marked lack of capacity to collect and analyse data on firearms trafficking. These findings suggest the need to re-evaluate how firearms trafficking is often perceived.