This article examines the changing nature of public health services and their relationship with the public in post-war Britain by an analysis of the exhibitions mounted by Medical Officers of Health (MOsH) in London. Focusing on the period 1948-71, the article explores a time when public health practice, and the problems it faced, were in flux. A decline in infectious disease and an increase in chronic conditions linked to lifestyle required a new role for public health services. Exhibitions were one of several methods that MOsH used to inform the public about dangers to their health, but also to persuade them to change their behaviour. The exhibition, though, offers a unique insight into the relationship between public health authorities and the public, as exhibitions brought MOsH into direct contact with people. It is suggested that in the MOsH exhibitions we can find signs of a new relationship between public health practitioners and the public. Whilst elements of the pre-war, often moralistic ideology of public health services could still be detected, there is also evidence of a more nuanced, responsive dynamic between practitioners and the people. By the end of the 1960s, 'the public' was increasingly being thought of as a collection of 'publics', including individuals, target groups and vocal respondents.