This chapter reviews various Wireless Sensor Networks (WSN) applications spanning different domains, namely health care, agriculture, environment, industry, and military. It discusses the problems of setting up WSNs for the health-care domain and describes the key applications. The chapter presents some applications from the agriculture domain. It provides an overview of application from the environmental domain. The chapter also provides a summary of applications from the industry domain. It focuses on applications from the military domains. The chapter discusses newly deployed and ongoing applications of WSNs. The health-care field is always looking for more efficient ways to provide patients with the best and most comfortable care possible. The medical field has also found many implementations for sensor networks. The pervasiveness of sensor networks continues into applications in disaster recovery. The most peculiar application of CodeBlue is the motion analysis sensor board. The field of medical diagnostics is another great potential area for using the sensor technology.