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 high credence services. A survey was carried out involving a convenience sample of 500 customers of private practice medical doctors from several specialties operating in 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 customer loyalty through RQ but there is also a direct effect between rapport and responsibility and loyalty. Findings present managerial implications. Future research should validate results in multi-context or multi-country studies.