Cloud-based services are becoming commonplace. Examples of these services include on-demand creation of virtual machines (VMs), backup of user data, and rapid deployment and automatic scaling of applications. These services are typically offered under three different service models: infrastructure as a service (IaaS), platform as a service (PaaS), and software as a service (SaaS) (Mell and Grance, 2011). Cloud providers, large and small, offer these services to individuals, small and medium businesses, and large enterprises. Each service is typically accompanied by a service-level agreement (SLA), which defines the service guarantees that a provider offers to its users.While some cloud service deployment models are better understood than others (e.g., IaaS is arguably the most understood service model at the time of writing of this chapter), by and large cloud services are rapidly evolving and hence not standardized. As a consequence, the services offered by providers vary. Even for services deemed similar across providers, the SLAs can vary considerably. Service-level agreements also serve as a marketing tactic to attract new customers, either by bundling together different services, or by offering attractive guarantees with small print that may not ultimately benefit a cloud consumer. Such groupings of SLAs make comparison across cloud providers even more difficult. Moreover, a cloud provider may offer a canned SLA to all its consumers, irrespective of their requirements or size. An entity running mission-critical applications on a cloud would likely require a different SLA from an entity that is just beginning to evaluate the use of a cloud-based service.In this chapter, we briefly explain the entities involved in cloud-based services (section 36.1.1). We describe elements of an SLA of a cloud-based service with detailed examples, which can help a cloud consumer in comparing SLAs of cloud-based services. We then give an overview of SLAs of two well known public cloud providers, namely, Amazon and Rackspace (section 36.3). Finally, we discuss future directions in cloud SLAs (section 36.4).