In 1948 the New South Wales government instituted an inquiry into the claims of John Braund – a 78-year-old self-described ‘quack’ – that his secret treatment had cured 317 cancer sufferers. The ‘Braund controversy’, as it became known, was one of Australia’s most prominent cases of medical fraud. This paper examines that controversy and its effects on cancer philanthropy, medical research, and especially on legislation regulating treatment providers up to the present. With the Braund controversy in mind, the New South Wales (NSW) parliament struggled to develop legislation that would protect patients and punish quacks but also allow for serendipitous, unorthodox discoveries. Recent decades saw new elements added to this calculus – allowing a wide-ranging health marketplace, and allowing patients to choose their therapies. This paper argues that the particular body of law legislatures used in regulating cancer treatment and how regulations were framed reflected the changing context of healthcare and illustrates the calculus legislatures have undertaken in regulating the health marketplace, variously factoring in public safety, serendipitous discovery, the authority of orthodox medicine, patient choice, and economic opportunity.