People with the FMR1 premutation are at increased risk to develop a neurodegenerative disease (fragile X-associated tremor/ataxia syndrome, FXTAS), reproductive health problems (in females), and potentially a range of other mental and general health conditions. This paper introduces the International Fragile X Premutation Registry (IFXPR), developed to facilitate research to better understand the premutation and its impact on human health, to facilitate clinical trial readiness, and to build community among carriers, family members, researchers, and clinicians around the world. Here, we describe the development and content of the IFXPR, characterize its first 747 registrants from 32 countries, and invite investigators to apply for recruitment support for their projects. (Professor David Hessl, https://jmg.bmj.com/content/early/2022/06/14/jmedgenet-2022-108568 )