Background: Incident benzodiazepine prescriptions in primary care for anxiety decreased between 2003-2018. However, from 2008, incident prescribing of benzodiazepines for anxiety increased among those aged 18-34. There are increasing concerns around prescribing of benzodiazepines. Further, although guidelines state benzodiazepines should only be prescribed short-term, in 2017, 44% of incident prescriptions were prescribed for longer than the recommended duration of two to four weeks. Aim: To understand when and why GPs prescribe benzodiazepines for anxiety in young adults. Design and setting: In-depth interviews with 17 GPs from ten practices in South West England. Method: Interviews were conducted by telephone or videocall. A topic guide was used to ensure consistency across interviews. Interviews were audio-recorded, transcribed verbatim and data analysed using reflexive thematic analysis. Results: GPs described caution in prescribing benzodiazepines for anxiety in young adults, but thought they had an important role in acute situations. GPs described caution in prescribing duration, but some thought longer-term prescriptions could be appropriate. GPs perceived that some young adults requested benzodiazepines and suggested this might be because they wanted quick symptom relief. GPs noted that refusing to prescribe felt uncomfortable and that the number of young adults presenting to general practice, already dependant on benzodiazepines, had increased. Conclusion: Patient-driven factors for prescribing benzodiazepines suggest there are current unmet treatment needs among young adults with anxiety. Given increases in prescribing in this age group, it may be timely to revisit the role of benzodiazepines in the management of people with anxiety in primary care.