Description The outsourcing market, especially Business Process Outsourcing (BPO), is growing every year. For decades, companies have successfully used outsourcing to generate significant savings. However, discussions with any employee will reveal some resentment of outsourcing. The aim of the study has been first to improve the understanding of some salient difficulties in Business Process Outsourcing relationships, with special reference to the perceived challenges of managing and monitoring Service Level Agreements in Swiss banking, and second to assist outsourcing banks and service providers in formulating and managing their outsourcing contracts. The study was designed to obtain, through interviews, descriptions and perceptions of experts in Swiss Banking Business Process Outsourcing. Given the nature of the topic but also because of practical constraints, the investigator elected to use a qualitative, interpretative, social constructionist research framework. An extensive review of the literature revealed that a variety of definitions of in-and out-sourcing exist. Some of these terms were used in academic writings and the business press interchangeably and had to be defined. Twenty-two practitioners were interviewed. The data were analysed and interpreted with the help of qualitative analysis software (NVivo). Subsequently, I compared my findings with those of the literature reviewed. Furthermore, a gap in the literature, namely that it generally does not deal with the perceived quality of the relationship, could be addressed and practical approaches for managing BPO relationships are suggested. Keywords Outsourcing, Business Process Outsourcing (BPO), relationship, Service Level Agreement (SLA) .