This tutorial provides a comprehensive examination of pilot studies, particularly those conducted for phase III clinical trials. Pilot studies, also known as "feasibility" or "vanguard" studies, are essential for assessing the safety, recruitment potential, and feasibility of international collaboration for multicenter trials. They help increase clinical experience with the study medication or intervention and are crucial for the success of large-scale trials. The paper covers the general reasons for conducting pilot studies, their relationships with proof-of-concept studies and adaptive designs, common challenges and misconceptions, criteria for evaluating success, frequently asked questions, ethical aspects, and recommendations for reporting results using the CONSORT format. The authors emphasize the importance of clear feasibility objectives, analytic plans, and explicit criteria for determining success, and caution against using pilot studies to estimate treatment effects or power calculations. The tutorial also discusses the ethical obligations researchers have to participants regarding the disclosure of the feasibility nature of pilot studies. Overall, the paper aims to guide researchers in designing and reporting pilot studies effectively.This tutorial provides a comprehensive examination of pilot studies, particularly those conducted for phase III clinical trials. Pilot studies, also known as "feasibility" or "vanguard" studies, are essential for assessing the safety, recruitment potential, and feasibility of international collaboration for multicenter trials. They help increase clinical experience with the study medication or intervention and are crucial for the success of large-scale trials. The paper covers the general reasons for conducting pilot studies, their relationships with proof-of-concept studies and adaptive designs, common challenges and misconceptions, criteria for evaluating success, frequently asked questions, ethical aspects, and recommendations for reporting results using the CONSORT format. The authors emphasize the importance of clear feasibility objectives, analytic plans, and explicit criteria for determining success, and caution against using pilot studies to estimate treatment effects or power calculations. The tutorial also discusses the ethical obligations researchers have to participants regarding the disclosure of the feasibility nature of pilot studies. Overall, the paper aims to guide researchers in designing and reporting pilot studies effectively.