Aim: Meaningful client-dietitian relationships are central to effective dietetic practice. The chronic disease management setting provides an opportunity to examine what is meaningful and how these relationships are constructed, because the dietitian and client generally have multiple interactions over an extended period of time. This study aimed to explore dietitians' perspectives of how they develop meaningful relationships with clients managing lifestyle-related chronic diseases. Methods: Study design and analysis were guided by Charmaz's constructivist grounded theory. Dietitians working in Australia with clients managing chronic diseases were recruited through initial, snowball and theoretical sampling. Online videoconference and telephone semi-structured interviews were conducted. Recorded interview transcripts were analysed using repeated reviews comprising initial, focused and theoretical coding and memoing. Results: Twenty-two dietitians were recruited. A conceptual model developed from the data showed the dietitian's role in developing the client-dietitian relationship is complex. Key elements were identified and described as ‘Sensing a Professional Chemistry’, and the dietitian's skills in ‘Balancing Professional and Social Relationships’ and ‘Managing Tension with Competing Influences’. Influences were categorised as relating to the client and dietitian as individuals (eg, their values), their support network and external contextual factors (eg, working with interpreters). Conclusion: Developing relationships with clients in the chronic disease context appears complex due to the dietitian's role of managing multiple interrelated elements and influential factors simultaneously. To deepen understanding, research should explore clients' perspectives of relationship development and how knowledge of practitioner-client relationships in other disciplines may be utilised to enhance dietetic service delivery.