A detailed analysis is made of the current ideas concerning floods of a special type. We examine sudden short-duration torrential floods, one of the most widespread and hazardous natural phenomena in the world characterized by a high rate of development, and by a short duration. It is shown that such floods are of the most widespread occurrence in the northern hemisphere in regions with a temperate and subtropical climate. It is established that such floods are in a primitive stage of study, which is testified by the fact that there is no general consensus as to what should be treated as a sudden flood. It is pointed out that a special term designating them is also absent in many countries. It is determined that the key formation conditions for sudden floods include intense short-duration cloudbursts, occurrence of a river basin in mountainous regions and a small drainage area; on this basis, it is suggested that they be termed sudden cloudburst floods. We suggest the scheme of natural factors for formation of sudden cloudburst floods and their differences from mudflows and floods of other types. It is determined that the main problems of investigating the formation mechanisms and forecasting the aforementioned floods are associated with the small spatiotemporal scale of these phenomena.Keywords: precipitation, drainage area, mudflow, hydrometeorological factors, lithologo-geomorphological factors.