Visual uncertainty representation and communication during nuclear and radiological emergencies face empirical and theoretical challenges. The work carried out focuses on visualisation of uncertainties as a decision support and communication tool.We represent uncertainty visually through maps and visual robustness indicators. An interdisciplinary approach was applied where both quantitative and qualitative methods were used to validate and test the tools developed in 6 different occasions/countries. The principles for building effective uncertainty representation and communication tools are presented. It is important to note that the visual approach offers a great opportunity to represent uncertainty to experts in the field of emergency planning especially in the nuclear/radiological one.