This paper examines how specific concepts of the self shape discussions about the ethics of changing sex. Specifically, it argues that much of the debate surrounding sex change has assumed a model of the self as authentic and/or atomistic, as demonstrated by both contemporary medical discourses and the recent work of Rubin (2003). This leads to a problematic account of important ethical issues that arise from the desire and decision to change sex. It is suggested that by shifting to a properly intersubjective and performative model of the self, we can better understand (1) the diagnosis of transsexuality; and (2) issues of success, failure and regret with regard to changing sex. The paper also reveals the important implications this shift has for how the relationship between medical practitioners and transindividuals is understood. The paper concludes by showing how the model of the self as authentic can individualise identity and thus downplay or overlook the tight intertwinement between self and other. A properly intersubjective, performative concept of the gendered self places other people at the centre of both an individual’s attempt at self-transformation and the ethical issues that arise during this process.