The objective of this paper is to test whether the effect of variables such as knowledge, attitudes, trust, risk perception, and psychometric risk characteristics changes in the different stages of risk-related information processing. A distinction is made between two information-processing steps, reception (measured as a person’s ability to retain the information communicated) and acceptance (measured as a person’s level of agreement with the communicated information). An empirical study was conducted, using a radiological accident (2008) in Belgium as a communication case study. Face-to-face interviews were conducted on a large sample of Belgian population representative with respect to province, region, level of urbanization, gender, age, and professionally active status (N = 1031) and among the population living in vicinity of the accident (N = 104). All factors were measured on reliable scales (Cronbach’s α > .75). The results demonstrate that knowledge was the driving factor only for the reception of risk messages, while heuristic predictors such as psychometric risk characteristics, attitudes, and trust were most influential for the acceptance of risk messages. It is discussed how the results will facilitate a more thorough understanding of information processing and how they could be used to design more focused risk communication strategies.