Background Generalist approaches can help address several challenges facing today’s primary care. However, GPs report insufficient support to deliver advanced generalist medicine (AGM) in daily practice, struggling within a healthcare system that imposes strict adherence to single-disease focused guidelines. Aim We aimed to examine the professional and educational experiences of newly qualified GPs attending a course on AGM to understand how to redesign primary care systems to support their generalist work. Design and Setting Qualitative study focusing on AGM in UK general practice (England), conducted in the context of the research evaluation of an online career development programme on AGM. Method We conducted 36 interviews and 6 focus groups with newly qualified GPs attending an online career development programme on AGM, and analysed data using framework analysis. Results Three tensions experienced by the participants were identified: tension between realistic and idealistic practice; tension between different decision-making paradigms; tension in the formation of the GPs’ professional identities. These were due to grey areas of practice deeply rooted in primary care systems – namely areas of work not adequately addressed by current education and service design. Conclusions Our findings have implications for tackling the general practice workforce crisis, highlighting that solutions targeting individual problems will not suffice by themselves. By making visible the grey areas of everyday general practice, we describe the changes needed to target tensions as described by the GPs in this study to ultimately enable, enhance and make visible the complex work of generalist medicine.