EDI is an important inter-organizational information system which is said to provide competitive advantage for the companies using it. However, in the early stage of EDI implementation, there are some obstacles which may slow down or even deter its adoption. This study identifies obstacles and reasons for using EDI in Hong Kong. Because Hong Kong is in an early stage of adopting EDI, the problems faced may be quite different from other countries, like the USA, where organizations have been using EDI for quite some time. Based upon a review of the literature and a Delphi survey, we constructed a questionnaire and sent it to 300 companies, asking respondents to rank the importance of the identified obstacles and to rate the benefits of using ED I. Forty eight completed questionnaires were returned. Data from them and from the Delphi survey were analyzed and compared. The results show that lack of knowledge of EDI is the top obstacle to EDI implementation; communication-related factors are the top reasons why companies adopt EDI.