Anxiety problems are prevalent among children and young people, yet few families access treatment. Parent-led interventions are one method of increasing access, but little is known about how outcomes and experiences of such interventions translate from tightly controlled research studies to the “real world” and, where it has been evaluated in “real world” settings, to what extent intervention delivery fully reflects routine practice. This systematic review identified 14 studies with broadly positive outcomes; however, there was a dearth of detail surrounding the nature of the “routine practice” settings. More research and thorough reporting are needed to close the research–implementation gap.