The main aim of this study is the assessment of an extreme precipitation event causing a flash flood in the Vernazza catchment, Cinque Terre on the 25th of October 2011. We utilized a rainfall-runoff model taking into account five important factors: i) the morphology, ii) the geological settings, iii) the landcover/ landuse distribution, iv) the soil characteristics, and v) the precipitation input. The model calculates the water balance for the soil surface, which results in the partitioning of rainfall in surface runoff and infiltration. The latter was regionalized based on measured soil infiltration data using a constant head permeameter. The runoff algorithm was implemented in a GIS environment supposing that evapotranspiration can be neglected for this event. We show that morphometric parameters yield valuable and important input information for the models and can be utilized as first hazard screening approach. Moreover, the results obtained provide important information for the preparation of plans and strategies of risk management in the Cinque Terre National Park.