Extreme phases of the El Niño Southern Oscillation (ENSO) show relationships with economic damages due to disasters worldwide. Climate forecasts can predict ENSO months in advance, enabling stakeholders to take disaster risk reducing actions. An understanding of risks during ENSO extremes is key for adequate response. Here, we review the effects of ENSO on disaster risks, including droughts and floods. We show that ENSO may increase the risk of water scarcity and low crop yields globally, and change the probabilities of extreme rainfall, and coastal and river flooding. We provide recommendations on how to reduce risks using ENSO forecasts.