This tutorial provides a comprehensive overview of pilot studies for phase III clinical trials. Pilot studies are essential for assessing the feasibility of large-scale studies, including safety, recruitment, and logistical aspects. They are often referred to as "feasibility" or "vanguard" studies and are crucial for planning and conducting successful phase III trials. The paper discusses the reasons for conducting pilot studies, their relationship with proof-of-concept studies and adaptive designs, common challenges and misconceptions, criteria for evaluating success, frequently asked questions, ethical considerations, and recommendations for reporting results. Pilot studies are typically small-scale investigations that help determine the feasibility of a larger study. They can be used to test methods and procedures, assess recruitment potential, evaluate surrogate markers, and identify optimal dosing for phase III trials. However, they should not be used to estimate treatment effects due to the risk of biased results from small sample sizes. Pilot studies should focus on feasibility rather than statistical significance. The paper emphasizes the importance of clear feasibility objectives, well-designed studies, and proper reporting. It also highlights the ethical responsibility of researchers to disclose the nature of pilot studies to participants. The authors recommend using the CONSORT format for reporting pilot study results, ensuring transparency and clarity in the presentation of findings. Overall, pilot studies are a vital step in the development of large-scale clinical trials, helping to ensure their success and avoid unnecessary resource expenditure.This tutorial provides a comprehensive overview of pilot studies for phase III clinical trials. Pilot studies are essential for assessing the feasibility of large-scale studies, including safety, recruitment, and logistical aspects. They are often referred to as "feasibility" or "vanguard" studies and are crucial for planning and conducting successful phase III trials. The paper discusses the reasons for conducting pilot studies, their relationship with proof-of-concept studies and adaptive designs, common challenges and misconceptions, criteria for evaluating success, frequently asked questions, ethical considerations, and recommendations for reporting results. Pilot studies are typically small-scale investigations that help determine the feasibility of a larger study. They can be used to test methods and procedures, assess recruitment potential, evaluate surrogate markers, and identify optimal dosing for phase III trials. However, they should not be used to estimate treatment effects due to the risk of biased results from small sample sizes. Pilot studies should focus on feasibility rather than statistical significance. The paper emphasizes the importance of clear feasibility objectives, well-designed studies, and proper reporting. It also highlights the ethical responsibility of researchers to disclose the nature of pilot studies to participants. The authors recommend using the CONSORT format for reporting pilot study results, ensuring transparency and clarity in the presentation of findings. Overall, pilot studies are a vital step in the development of large-scale clinical trials, helping to ensure their success and avoid unnecessary resource expenditure.