An unprecedented precipitation event in Rio Grande do Sul, Brazil, between April and May 2024 caused widespread floods and landslides. This extreme event impacted 96% of the state’s municipalities, affecting approximately 2.4 million people and resulting in 183 deaths. This article reports the magnitude of this extreme event, focusing on the preliminary results of a comprehensive landslide inventory. Our analysis revealed that this event triggered 15,376 landslides across approximately 18,000 km2, with 16,862 landslide initiation points. This event represents the largest landslide occurrence ever recorded in Brazil, measured by quantity. This study provides a scientific analysis of the event’s scale, spatial distribution and the associated topographic, environmental and infrastructural conditions.