Organizational adoption of innovations does not always follow easily comprehendible patterns. This is often the case with interorganizational information systems (IOS), where adoption is dependent on attributes related both to the organization and to its environment. The present study operationalizes the Tornatzky and Fleischer (1990) model for organizational adoption in order to investigate reasons for adoption and non-adoption among businesses in the Danish steel and machinery industry. This particular industry segment had been subject to massive information campaigns focusing on the benefits of IOS in the form of EDI from business associations. The study suggests that environmental and organizational attributes rather than technological attributes are the main determining forces for adoption of EDI.