The CONSORT Statement (CONsolidated Standards for Reporting Trials) is a reporting guideline designed to improve the transparency and quality of the reporting of randomised controlled trials (RCTs). In this article, we present an extension to the CONSORT Statement for randomised pilot and feasibility trials conducted in advance of a future definitive RCT. The checklist applies to any randomised study in which a future definitive RCT, or a part of it, is conducted on a smaller scale, regardless of its design (eg cluster, factorial, cross-over) or the terms (eg pilot, feasibility, trial, study) used by authors to describe the study. The extension does not directly apply to internal pilot studies built into the design of a main trial, non-rand...