The development of successful long-term relationships with customers is considered to be a sustainable competitive advantage and the enhancement of relationship quality (RQ) is a very important issue for firms today especially in services. The purpose of this study is to test the effect of respect and rapport on RQ and customer loyalty (CL) in private doctor-patient relationships. A survey was carried out involving a convenience sample of 600 customers of professional doctors from several specialties operating in the district of Athens, Greece. Data was analysed with PLS-PM. Results showed that Rapport is the most significant antecedent of RQ followed by two dimensions of respect, responsibility and understanding. Also, respect and rapport indirectly affect CL through RQ but there is also a direct effect between rapport and responsibility and CL. Findings present managerial implications. Future research should validate results in multi-context or multi-country studies.