Although the adoption of e-procurement has rapidly increased in recent years, companies face different challenges associated with the advent and use of eprocurement. One is that most companies only apply single e-procurement functions. The analysis by Wyld (2004) shows that in the USA only 30 percent of the companies surveyed use e-procurement systems for requests for quotations, online auctions (25 percent) or e-markets (33 percent). A second challenge is that, despite the overwhelming evidence which shows the advantages of e-procurement systems, proprietary systems such as EDI continue to persist, and have to be included in a company’s overall e-procurement infrastructure. To do so, companies need to know the critical success factors in implementing e-procurement strategies, processes and systems.