In a mass casualty event, there will be at-risk populations that will require unique triage, treatment and consequence management to minimise immediate and long-term health effects. This statement is particularly true for radiological/nuclear (R/N) disasters where individuals exhibit a broad range of physiological responses to radiation exposure. For example, immunocompromised individuals will experience more detrimental radiation health effects; however, it is not always possible to definitively identify these individuals at the time of triage. Immediate and long-term consequence management for these individuals may require unique and potentially limited resources. Thus, at the time of an R/N event, it is crucial to assist community planners by: (a) rapidly identifying at-risk individuals who may have been exposed; (b) determining the dose and individual-specific health risks associated with radiation exposure; (c) identifying additional resources needed to deal with unique, population-specific requirements; and (d) developing treatment strategies in keeping with the rules of ‘supply and demand’. A comprehensive approach to identifying issues relevant to the R/N emergency preparedness for dealing with at-risk populations will be discussed with the aim of defining future research objectives.