During the late nineteenth century, many British physicians rigorously experimented with hypnosis as a therapeutic practice. Despite mounting evidence attesting to its wide-ranging therapeutic uses publicised in the 1880s and 1890s, medical hypnosis remained highly controversial. After a decade and a half of extensive medical discussion and debate surrounding the adoption of hypnosis by mainstream medical professionals – including a thorough inquiry organised by the British Medical Association – it was decisively excluded from serious medical consideration by 1900. This essay examines the complex question of why hypnosis was excluded from professional medical practice by the end of the nineteenth century. Objections to its medical adoption rarely took issue with its supposed effectiveness in producing genuine therapeutic and anaesthetic results. Instead, critics’ objections were centred upon a host of social and moral concerns regarding the patient’s state of suggestibility and weakened ‘will-power’ while under the physician’s hypnotic ‘spell’. The problematic question of precisely how far hypnotic ‘rapport’ and suggestibility might depart from the Victorian liberal ideal of rational individual autonomy lay at the heart of these concerns. As this essay demonstrates, the hypnotism debate was characterised by a tension between physicians’ attempts to balance their commitment to restore patients to health and pervasive middle-class concerns about the rapid and ongoing changes transforming British society at the turn of the century.