In this chapter, we focus on the use of formal methods for cyber-physical systems (CPS). These systems are composed of both software and hardware components that interact with their physical environment. Thus, several challenges in terms of security, reliability, and performance can arise when using these systems. In this regard, the use of formal methods could present an effective solution to guarantee these crucial properties. Formal methods are indeed rigorous mathematical methods that allow the rigorous verification and validation of different types of these systems. In particular, this chapter focuses on the use of formal methods to guarantee the proper functioning of CPSs in unforeseen environments and conditions. We begin by providing an overview of CPSs and an overview of formal methods. Next, we highlight the benefits of using formal methods for CPSs providing two specific examples: a first example about Controlling Drone Access to Critical Zones amd a second example about Optimizing Traveler Behavior Between Two Cities. We then identify the main challenges and limitations encountered in this context. Finally, we present some recommendations and advice for users of formal methods for CPSs as well as future directions in this field.