Background Trans and gender-diverse people face multiple barriers within health care. Primary care practitioners are key to providing health care to trans and gender-diverse people but they often lack training in, and understanding of, trans identities and healthcare options. Few studies have examined health professionals' understanding of the barriers that exist in health care for trans and gender-diverse people. Aim To map out barriers to providing good-quality health care to trans and gender-diverse people, and explore ways to address them. Design and setting A qualitative interview study involving 20 health professionals working with young trans and gender-diverse people. Method Participants were recruited through purposive and snowball sampling. Data were generated using semi-structured qualitative interviews. A thematic analysis involved coding and categorising data using NVivo (version 12) software and further conceptual analysis in which developing themes were identified. Results Four barrier domains to good-quality care for trans and gender-diverse people were identified: Structural (related to lack of guidelines, long waiting times, and shortage of specialist centres); educational (based on lack of training on trans health); cultural and social (reflecting negative attitudes towards trans people); and technical (related to information systems and technology). Conclusion There is an urgent need to address the barriers trans and gender-diverse people face in health care. Structural-level solutions include health policy, professional education, and standards; at the practice level, GPs can act as potential drivers of change in addressing the cultural and technical barriers to better meet the needs of their trans and gender-diverse patients.