A feasibility study is defined as a study asking “whether something can be done, should we proceed with it, and if so, how” and a pilot study as “a study in which a future trial or part of it, is conducted on a smaller scale.” The reasons for conducting a pilot trial include procedural, resource- or management-related, scientific, and methodological rationales. Unfortunately, pilot and feasibility studies have received little attention or suboptimal scrutiny in the surgical literature. In this chapter, we give an introduction to pilot and feasibility studies covering their definition, importance and necessity, current practice in the literature, key considerations for designing a pilot trial, and how to report a pilot trial. We also provide a clinical scenario as a practical example using the CONSORT extension checklist.