Purpose ' The purpose of this paper is to focus on the critical, yet under-researched dimension of relationship development, being interpersonal liking. Liking has been found to positively influence relationship success. However, these issues have not been extensively explored in the banking sector. Design/methodology/approach ' A case study methodology was adopted for this research. The unit of analysis used was the relationship dyad that exists between a business lender at a major international bank and their customer. Ten case studies were conducted with a range of techniques in an attempt to increase the reliability and validity of the findings. Findings ' Findings suggest that the interplay between similarities, communication, professionalism, trust and personality are the driving forces leading to interpersonal liking in business lender-customer relationships. Further, the outcomes of interpersonal liking emerged as increased commitment and cooperation in the relationship and a growth in business referrals for the bank lender. These findings contribute to the limited theory on interpersonal liking. Research limitations/implications ' Several limitations emerged due to the nature of the research undertaken. These include the examination of relationships in only one major bank in Australia and the research undertaken uses cross-sectional not longitudinal data. Practical implications ' These findings have implications for human resource management policies when recruiting personnel in relationship development rolls in the banking sector. Further, training programs aimed at developing interpersonal liking skills could be fashioned. Finally, dissemination of these findings in the banking sector would allow the important concept of interpersonal liking to gain more academic and practical attention. Originality/value ' This paper identifies what interpersonal liking is. Findings for three research questions are presented followed by an explanaof the methodology adopted.