In this report the fire problems in palletized warehouses have been studied by litterature investigation. A large number of fire tests as well as real fires in several types of warehouses have been studied. It is extremely doubtful if manual action with hose streams could alone be able to bring fires in high racked storages under control. Hence the importance is attached to tests with sprinkler. Use of high expansion foam in warehouse fires has also been illustrated. The test results depend largely on the stock orientation, the height of the piles and the way of piling. Drop size in the sprinkler spray plays very important role for test results, too. To quickly bring the fire under control, a high initial water density is needed. It should be aimed on the right place in the right way. Early Suppression Fast Response (ESFR) sprinkler system turns out to be a reliable solution of this problem. So called Quick Acting sprinkler system with so called line detector could also be very reliable in this occasion.