Most ethics committees which review research protocols insist that potential research participants reserve unconditional or absolute 'right' of withdrawal at any time and without giving any reason. In this paper, I examine what consent means for research participation and a sense of commitment in relation to this right to withdraw. I suggest that, once consent has been given (and here I am excluding incompetent minors and adults), participants should not necessarily have unconditional or absolute rights to withdraw. This does not imply that there should be a complete absence of rights, or, indeed, an abandonment of the right to withdraw. The point of this paper is to show that the supposed unconditional or absolute nature of these rights may be self-defeating and so fail to respect the autonomy of participants. In addition, and on a more positive note, I suggest that, attaching certain conditions on the right to withdraw, may better respect the autonomy of these participants by underlining the idea that autonomy is more than mere whim or indifference to the fate of others. On the contrary, research staff are currently unable to 'push' participants, who may merely have logistical difficulties unrelated to the research itself, but who really want to stay the course, for fear of coercing them. Furthermore, researchers now try to 'screen out' people they think may be unreliable to protect the science of the study and so groups at risk of dropping out may be unfairly denied access to research treatments. I conclude that on-going negotiation between the relevant parties could be on balance the only truly acceptable way forward but concede certain important limitations to take into account.