Implementing an e-ordering system in a successful way, i.e., managing the implementation process, overcoming the barriers that occur and achieving a satisfactory compliance rate, is not as easy as some consultants and software companies claim. Understanding how a given organisation has managed the implementation process (resulting in a satisfactory compliance rate) may help other organisations achieve the successful implementation of e-ordering systems. The present paper describes the implementation of an e-ordering system in a large pharmaceutical organisation, discussing the problems it faced and how those were overcome. An analysis of the success factors found in previous research is presented, revealing one area that influences implementation success to a larger extent: the end user uptake. A four-year longitudinal case study is presented, which is based on interviews, observations made in daily work, at meetings and training sessions, and other documentation.