Service-Oriented Architecture (SOA) has been adopted in many critical information systems in many application domains, such as health care, scientific research, e-business, and homeland security. While SOA has many advantages, such as rapid composition, deployment, and dynamic adaptation of service-based systems, many issues on security, privacy, risk, and trust in service-oriented environments need to be resolved in order to achieve trustworthy information systems. In this address, the privacy, security, risk, and trust and their relationship in service-oriented environments will be discussed. The challenging issues and the current state of the art of addressing these issues will be presented. Future directions of research in this area will also be discussed.