A feasibility studyFeasibility 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 futuretrialTrialor part of it, is conducted on a smaller scale’. The reasons for conducting a pilot trialPilot trial include procedural, resource- or management-related, scientific and methodological rationales. Unfortunately, pilot studies have received little attention or suboptimal scrutiny in the surgical literature. In this chapter, we give an introduction to pilot studies covering their definition, importance or necessity of conducting a pilot trial, 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.