Public responses to large-scale radiological incidents are often thought to be disproportionate to the objective risk and can involve widespread societal disruption. Recent experiences of the (200)Po incident in central London suggest that public responses depend heavily on the nature of the incident and the effectiveness of risk communication efforts. This paper describes the outcome of several studies done in the aftermath of the (200)Po incident that suggest the reaction of the public on this occasion was muted, even for those directly affected. However, the desire for accurate, up-to-date and individually-tailored information was strong, and satisfaction with the efforts of the responding agencies was mediated by this information provision. A small minority of individuals was difficult to reassure effectively. This group may confer a particular drain on resources. Lessons for the risk communication efforts of public health responders are identified, in particular the importance of helping individuals to identify their risk of exposure, understand the difference between acute and chronic effects of exposure, and appreciate the meaning of any test results. Attempts at providing reassurance in the absence of specific information are likely to be counterproductive in any future radiological incident.