Service Oriented Architecture ("SOA") has been viewed as a strategic approach to IT that provides increased flexibility. However, there is scant research evidence of SOA adoption leading to tangible performance benefits across a cross section of firms. We fill this research gap by empirically analyzing the impact of SOA adoption on the performance of electronic supply chains for a cross section of large US firms. We find that adoption of SOA does lead to better performance of the electronic supply chain. We also find that SOA moderates firm?s ability to leverage electronically integrated customers to achieve better electronic supply chain performance. Further, we show that the impact of SOA adoption is fully mediated through its moderation effect on the firm?s ability to leverage electronically integrated customers to achieve higher electronic supply chain performance. Lastly, the paper discusses how IT managers can make informed SOA adoption decisions.