Windows Azure has been validated for compliance with the Payment Card Industry (PCI) Data Security Standards (DSS) by an independent Qualified Security Assessor (QSA).
The PCI DSS is the global standard that any organization of any size must adhere to in order to accept payment cards, and to store, process, and/or transmit cardholder data. By providing PCI DSS validated infrastructure and platform services, Windows Azure delivers a compliant platform for you to run your own secure and compliant applications. You can now achieve PCI DSS certification for those applications using Windows Azure.
Visit the Trust Center for a full list of in scope features or for more information on Windows Azure security and compliance.
Read more on Scott Guthrie’s blog.