This article uses the mass-media career of the British psychiatrist David Stafford-Clark (1916-1999) as a case study in the exercise of cultural authority by celebrity medical professionals in post-war Britain. Stafford-Clark rose to prominence in the mass media, particularly through his presenting work on medical and related topics for BBC TV and Radio, and was in the vanguard of psychiatrists and physicians who eroded professional edicts on anonymity. At the height of his career, he traded upon his celebrity status, and consequent cultural authority, to deliver mass media sermons on a variety of social, cultural, and political topics. Stafford-Clark tried to preserve his sense of personal and intellectual integrity by clinging to a belief that his authority in the public sphere was ultimately to be vindicated by his literary, intellectual, and spiritual significance. But as his credibility dwindled, he came to distrust the cultural intermediaries, such as broadcasters and publishers, who had supported him.