Pharmacists have an integral role in clinical decision-making. Over time, pharmacists have been more involved in patient-centered care owing to the increased scope of practice and the recognition that pharmacists being involved improves health outcomes for patients. Pharmacists are the most accessible health care professionals to the public; therefore, it is essential that pharmacists not only know how to make a decision but also to make an appropriate one. Drawing from various tools and resources, this chapter aims to show the extensive role that pharmacists have in clinical decision-making and the processes that go into making a decision. In addition, the thought processes that clinicians go through to make clinical decisions will be discussed. Specifically, it will discuss the critical thinking process, shared decision-making, the cognitive biases, factors, and barriers that impact the way pharmacists make a decision.