There exists a lack of consensus regarding a clear and precise definition of regenerative medicine. We suggest here a definition developed by the authors with input from researchers in the various contributing disciplines. This definition emphasizes the interdisciplinarity of the field, its goal of restoring impaired function, and the wide variety of technologies that can contribute to achieving this goal. By highlighting the lack of agreement regarding a definition of regenerative medicine, and by proposing our own definition, we hope to stimulate discussion on the subject within the field and to encourage the regenerative medicine community to work together to develop a consensus definition. We believe that a clear definition of regenerative medicine could help to unify the field and is essential to facilitate understanding among policy makers, funding agencies and the general public, as well as individuals from scientific and medical disciplines.