This study investigates a special class of Inter-Organizational Systems, Electronic Data Interchange (EDI) systems. The major objective of this research is to identify the factors that facilitate or inhibit the adoption of an EDI system. A research model is developed to investigate the research questions identified. The adoption of EDI systems is assumed to be affected by four contextual factors: 1. general characteristics of the industry in which a firm operates, 2. EDI-related industry characteristics, 3. general characteristics of the firm, and 4. information technology (IT) related firm characteristics. The findings of this study provide strong supporting evidence that most of the variables proposed and tested in the study are important factors affecting the adoption of EDI systems.