This research aims to evaluate children’s awareness and preparedness toward potential flood risks in Zagreb, Croatia, and to identify key factors in future education for Disaster Risk Reduction (DRR) in the city. In 1964, Zagreb experienced a large flood leading to 17 casualties. There have been no major floods since the national government implemented flood protection, however, the river water levels rise markedly during unexpected heavy rainfall. Although various actions are ongoing in Croatia to raise children’s awareness of natural disasters, very little systematic research can be found on this important topic, especially vulnerability, awareness and preparedness of young generation. Hence, a social survey of children 14–17 years old was conducted in Zagreb. The findings suggest that a fear of extreme weather and preparation status are somewhat co-related. Although 75% of the respondents were aware of the possibility of future floods, preparedness among them was disproportionate to their awareness and there was a gender gap in preparation status. It was concluded that the use of experimental, visual tools would be the best DRR method to educate the children of Zagreb by giving them a clearer understanding of the potential flood risks with information from materials compiled by the Croatian government.